Antibiotic-associated Gut Dysbiosis.

The human gut microbiota plays a crucial role in maintaining overall health. However, the widespread use of antibiotics has raised concerns about its impact on the microbial ecosystem. This review explores the multifaceted relationship between antibiotics and gut dysbiosis, highlighting the mechanisms underlying these interactions and their implications for human health. Antibiotics, while invaluable in treating infections, disrupt the gut microbiota by indiscriminately targeting both harmful and beneficial microorganisms. This disturbance leads to a reduction in microbial diversity, altered metabolite production, and compromised immune responses, resulting in a state referred to as dysbiosis. Broad-spectrum antibiotics tend to induce more severe dysbiosis compared to narrow-spectrum agents. Antibiotic-induced dysbiosis has been linked to the onset and progression of these disorders, emphasizing the far-reaching consequences of microbial imbalance. The review highlights various strategies to mitigate the adverse effects of antibiotics on gut health, like probiotics, fecal microbiota transplantation (FMT), and phage therapy, as promising approaches to restore and maintain a balanced gut microbiota. How to cite this article: Ramakrishna BS, Patankar R. Antibiotic-associated Gut Dysbiosis. J Assoc Physicians India 2023;71(11):62-68.

Assessment of small intestinal bacterial overgrowth in chronic pancreatitis patients using jejunal aspirate culture and glucose hydrogen breath test.

BACKGROUND: A subset of chronic pancreatitis patients respond poorly to pancreatic enzyme replacement therapy. Small intestinal bacterial overgrowth (SIBO) is considered to be one of the major reasons for this poor response. Previous studies have reported a wide range of prevalence of SIBO in patients with chronic pancreatitis. We aimed to assess the prevalence of SIBO in chronic pancreatitis using quantitative jejunal aspirate culture and glucose hydrogen breath test (GHBT). The sensitivity and specificity of GHBT for the diagnosis of SIBO in chronic pancreatitis were also estimated. METHODS: Newly diagnosed chronic pancreatitis patients were recruited into the study. A detailed history and relevant laboratory tests were done. All patients underwent an endoscopy and jejunal fluid aspiration for bacterial cultures and GHBT to detect SIBO. The results of GHBT were compared with jejunal fluid aspirate culture. RESULTS: The jejunal aspirate culture was positive in 18/48 (37.5%) patients while the GHBT showed that 14/48 (29%) patients had SIBO. The sensitivity, specificity, positive and negative predictive value of GHBT in our study was 44.4, 80, 57.14 and 70.59%, respectively. CONCLUSIONS: SIBO is not uncommon in chronic pancreatitis patients. One-third of our study population had SIBO. GHBT has low sensitivity but had high specificity in the diagnosis of SIBO in chronic pancreatitis.

Vitamin D status in Kancheepuram District, Tamil Nadu, India.

BACKGROUND: Vitamin D has multifarious roles in maintenance of health and prevention of disease. The present study was undertaken to assess the vitamin D status of a rural adult south Indian population and to identify its associations with socioeconomic status and cultural practices. METHODS: Between June 2015 and July 2016, 424 healthy adults residing in Kattankulathur block in Tamil Nadu, India, provided venous blood samples and answered questions by personal interview. 25-hydroxy vitamin D was estimated by ELISA. RESULTS: Fifty nine (13.9%) of the 424 participants had 25OHD levels below 12 ng/mL (vitamin D deficient) and 175 (41.3%) had 25OHD levels between 12 to 20 ng/mL (vitamin D insufficiency). In univariate analysis, demographic factors associated with vitamin D status included education, occupation, socioeconomic class, and birthplace; lifestyle factors included sun exposure time, skin surface exposed to sunlight, use of sunscreen, awareness of vitamin D, and consumption of fish; and hygiene related factors included source of drinking water, availability of tap water at home, and closed toilet at home. In ordinal logistic regression, the following variables were found to be independently associated with vitamin D sufficiency: Duration of daily sun exposure below 30 min (Odds ratio 0.31, 95% confidence intervals 0.14-0.71, P = 0.006), sun exposure 30-60 min (OR 0.49, 95% CI 0.30-0.80, P = 0.004), male gender (OR 2.00, 95% CI 1.30-3.09, P = 0.002), higher level of education (OR 0.80, 95% CI 0.69-0.94, P = 0.005), non-consumption of fatty fish (OR 0.48, 95% CI 0.24-0.85, P = 0.035) and presence of closed toilet system at home (OR 0.59, 95% CI 0.37-0.93). CONCLUSION: VDD and VDI are highly prevalent in this rural Indian community. The study identifies socioeconomic and behavior patterns that negatively impact vitamin D sufficiency, thus providing a basis for targeted intervention.

Faecal microbiota of healthy adults in south India: Comparison of a tribal & a rural population.

BACKGROUND & OBJECTIVES: The relevance of the gut microbiota to human health is increasingly appreciated. The objective of this study was to compare the gut microbiota of a group of adult tribals with that of healthy adult villagers in Tamil Nadu, India. METHODS: Faeces were collected from 10 healthy tribal adults (TAs) in the Jawadhi hills and from 10 healthy villagers [rural adults (RAs)] in Vellore district, Tamil Nadu. DNA was extracted, and 456 bp segments comprising hypervariable regions 3 and 4 of the 16S rRNA gene were amplified, barcoded and 454 sequenced. RESULTS: Totally 227,710 good-quality reads were analyzed. TAs consumed a millets-based diet, ate pork every day, and did not consume milk or milk products. RAs consumed a rice-based diet with meat intake once a week. In both groups, Firmicutes was the most abundant phylum, followed by Proteobacteria, Bacteroidetes and Actinobacteria. The median Firmicutes-to-Bacteroidetes ratio was 34.0 in TA and 92.9 in RA groups. Actinobacteria were significantly low in TA, possibly due to non-consumption of milk. Clostridium constituted the most abundant genus in both groups, but was significantly more abundant in TAs than RAs, while Streptococcus was significantly more abundant in RA (P<0.05). Analyses of genetic distance revealed that the microbiota were distinctly different between TA and RA, and principal component analysis using 550 distinct taxonomically identifiable sequences revealed a clear separation of microbiota composition in the two groups. Phylogenetic analysis of major microbiota indicated clustering of microbial groups at different major branch points for TAs and RAs. INTERPRETATION & CONCLUSIONS: Phylum Firmicutes and genus Clostridium constituted the bulk of the faecal microbiota, while significant differences in composition between the groups were probably due to differences in diet and lifestyle.

Intermittent Directly Observed Therapy for Abdominal Tuberculosis: A Multicenter Randomized Controlled Trial Comparing 6 Months Versus 9 Months of Therapy.

BACKGROUND: The duration of treatment of gastrointestinal tuberculosis continues to be a matter of debate. The World Health Organization advocates intermittent directly observed short-course therapy (DOTs), but there is a lack of data of its efficacy in abdominal tuberculosis. We therefore conducted a multicenter randomized controlled trial to compare 6 months and 9 months of antituberculosis therapy using DOTs. METHODS: One hundred ninety-seven patients with abdominal tuberculosis (gastrointestinal, 154; peritoneal, 40; mixed, 3) were randomized to receive 6 months (n = 104) or 9 months (n = 93) of antituberculosis therapy using intermittent directly observed therapy. Patients were followed up 1 year after completion of treatment to assess recurrence. Patients were evaluated for primary endpoint (complete clinical response, partial response, and no response) and secondary endpoint (recurrence of the disease at the end of 1 year of follow-up). RESULTS: Baseline characteristics were similar between the 2 randomized groups. There was no difference between the 6-month group and 9-month group in the complete clinical response rate on per-protocol analysis (91.5% vs 90.8%; P = .88) or intent-to-treat analysis (75% vs 75.8%; P = .89). Only 1 patient in the 9-month group and no patients in the 6-month group had recurrence of disease. Side effects occurred in 21 (21.3%) and 16 (18.2%) patients in the 6-month and 9-month groups, respectively. CONCLUSIONS: There was no difference in efficacy of antituberculosis therapy delivered for either 6 months or 9 months in either gastrointestinal or peritoneal tuberculosis, confirming the efficacy of intermittent directly observed therapy. CLINICAL TRIALS REGISTRATION: NCT01124929.

Alterations of mucosal microbiota in the colon of patients with inflammatory bowel disease revealed by real time polymerase chain reaction amplification of 16S ribosomal ribonucleic acid.

BACKGROUND & OBJECTIVES: Alterations in microbial communities closely associated with the intestinal mucosa are likely to be important in the pathogenesis of inflammatory bowel disease (IBD). We examined the abundance of specific microbial populations in colonic mucosa of patients with ulcerative colitis (UC), Crohn's disease (CD) and controls using reverse transcription quantitative polymerase chain reaction (RT-qPCR) amplification of 16S ribosomal ribonucleic acid (16S rRNA). METHODS: RNA was extracted from colonic mucosal biopsies of patients with UC (32), CD (28) and patients undergoing screening colonoscopy (controls), and subjected to RT-qPCR using primers targeted at 16S rRNA sequences specific to selected microbial populations. RESULTS: Bacteroides-Prevotella-Porphyromonas group and Enterobacteriaceae were the most abundant mucosal microbiota. Bacteroides and Lactobacillus abundance was greater in UC patients compared with controls or CD. Escherichia coli abundance was increased in UC compared with controls. Clostridium coccoides group and C. leptum group abundances were reduced in CD compared with controls. Microbial population did not differ between diseased and adjacent normal mucosa, or between untreated patients and those already on medical treatment. The Firmicutes to Bacteroidetes ratio was significantly decreased in both UC and CD compared with controls, indicative of a dysbiosis in both conditions. INTERPRETATION & CONCLUSIONS: Dysbiosis appears to be a primary feature in both CD and UC. Microbiome-directed interventions are likely to be appropriate in therapy of IBD.

Probiotic potential of lactic acid bacteria present in home made curd in southern India.

BACKGROUND & OBJECTIVES: The human gut microbiota play a significant role in nutritional processes. The concept of probiotics has led to widespread consumption of food preparations containing probiotic microbes such as curd and yogurt. Curd prepared at home is consumed every day in most homes in southern India. In this study the home-made curd was evaluated for lactic acid bacteria (LAB) with probiotic potential. METHODS: Fifteen LAB (12 lactobacilli, 1 l0 actococcus , 2 Leuconostoc) and one yeast isolated from home-made curd were evaluated for resistance to acid, pepsin, pancreatin and bile salts; antimicrobial resistance; intrinsic antimicrobial activity; adherence to Caco-2 epithelial cells; ability to block pathogen adherence to Caco-2 cells; ability to inhibit interleukin (IL)-8 secretion from HT-29 epithelial cells in response to Vibrio cholerae; and ability to induce anti-inflammatory cytokine expression in THP-1 monocyte cells. RESULTS: Lactobacillus abundance in fermenting curd peaked sharply at 12 h. Nine of the strains survived exposure to acid (pH 3.0) for at least one hour, and all strains survived in the presence of pancreatin or bile salts for 3 h. None showed haemolytic activity. All were resistant to most antimicrobials tested, but were sensitive to imipenem. Most strains inhibited the growth of Salmonella Typhimurium while five inhibited growth of V. cholerae O139. Seven strains showed adherence to Caco-2 cells ranging from 20-104 per cent of adherence of an adherent strain of Escherichia coli, but all inhibited V. cholerae adherence to Caco-2 cells by 20-100 per cent. They inhibited interleukin-8 secretion from HT-29 cells, in response to V. cholerae, by 50-80 per cent. Two strains induced IL-10 and IL-12 messenger ribonucleic acid (mRNA) expression in THP-1 cells. INTERPRETATION & CONCLUSIONS: LAB in curd had properties consistent with probiotic potential, but these were not consistent across species. LAB abundance in curd increased rapidly at 12 h of fermentation at room temperature and declined thereafter.

Clostridium leptum group bacteria abundance and diversity in the fecal microbiota of patients with inflammatory bowel disease: a case-control study in India.

BACKGROUND: Alterations in the fecal bacterial flora occur in inflammatory bowel disease (IBD). We examined the abundance and diversity of Clostridium leptum group, an important group of carbohydrate-fermenting bacteria, in the feces of patients with IBD and compared them with healthy controls. METHODS: Seventeen healthy controls (HC), 20 patients with Crohn's disease (CD) and 22 patients with ulcerative colitis (UC) participated in the study. DNA extracted from fecal samples was amplified by PCR targeting 16S rRNA gene sequences specific to C. leptum group. The PCR product was subjected to temporal temperature gradient electrophoresis (TTGE) and the number and position of individual bands were noted and diversity was estimated. The identity of bands at different positions was confirmed by cloning and sequencing. Real time quantitative PCR with Mesa Green, targeted at specific 16S rRNA gene sequences, was used to quantitate C. leptum group and its most prominent constituent, Faecalibacterium prausnitzii. RESULTS: Twenty five different operational taxonomic units (OTUs, equivalent to species) were identified constituting the C. leptum group in these participants. Their sequences were deposited in GenBank [accession numbers GQ465348 to GQ465370]. OTU number was significantly reduced in CD (7.7 ± 3.7, mean ± SD) and UC (9.0 ± 3.0) compared to HC (11.9 ± 2.2) (P=0.0005). The Simpson D index of alpha diversity was not significantly different between the three groups. Total numbers of C. leptum group bacteria and F. prausnitzii were reduced in both CD and UC compared to HC (P=0.0036 and P<0.0001 respectively). Disease activity did not influence numbers of C. leptum or F. prausnitzii in patients with CD or UC. CONCLUSION: C. leptum numbers and diversity were significantly reduced in both CD and UC suggesting that alterations noted were not specific to one disease. This could contribute to reduced short chain fatty acid production in IBD.

Role of the gut microbiota in human nutrition and metabolism.

The human gastrointestinal tract harbors trillions of bacteria, most of which are commensal and have adapted over time to the milieu of the human colon. Their many metabolic interactions with each other, and with the human host, influence human nutrition and metabolism in diverse ways. Our understanding of these influences has come through breakthroughs in the molecular profiling of the phylogeny and the metabolic capacities of the microbiota. The gut microbiota produce a variety of nutrients including short-chain fatty acids, B vitamins, and vitamin K. Because of their ability to interact with receptors on epithelial cells and subepithelial cells, the microbiota also release a number of cellular factors that influence human metabolism. Thus, they have potential roles in the pathogenesis of metabolic syndrome, diabetes, non-alcoholic fatty liver disease, and cognition, which extend well beyond their traditional contribution to nutrition. This review explores the roles of the gut microbiota in human nutrition and metabolism, and the putative mechanisms underlying these effects.

Long-term safety and effectiveness of azathioprine in the management of inflammatory bowel disease: A real-world experience.

Background and Aim: Azathioprine (AZA) forms the cornerstone for maintenance of sustained remission in inflammatory bowel disease (IBD). There is apprehension regarding the long-term effectiveness and safety of AZA in IBD. We present our experience with AZA use and outcomes in a cohort of IBD patients followed up over a long period of time. Methods: Records of 507 IBD patients under treatment at a single, tertiary care center in south India between 2013 and 2022 were evaluated retrospectively. Long-term compliance, tolerance, clinical outcome at the point of last follow-up, type and duration to the onset of adverse events, and subsequent amendment to treatment with regard to AZA were analyzed. Results: Of 507 patients with IBD, 320 patients (207 Crohn's disease [CD], 113 ulcerative colitis [UC]) who received AZA were included. The median follow-up was 41 months (interquartile range 15.5-77.5). Total duration of exposure was 1359 patient-years with median usage of 33 months. Of the patients, 26.9% received AZA for >5 years. Mean initiation and maximum doses of AZA were 0.97 and 1.72 mg/kg/day. Among the participants, 20.6% experienced side effects, including myelotoxicity (7.2%) and gastrointestinal intolerance (5.6%). Six patients developed malignancy. Among the side effects, 39.4% of side effects were dose-dependent. Among the patients, 38.1% had relapses requiring pulse corticosteroid therapy, and 16.2% had more than one relapse after commencement of AZA. AZA was continued till the last follow-up in 76.5%. Among the patients, 49.7% (UC 51.3, CD 48.8) attained durable remission without biologics, and 5.3% continued to have active disease. Conclusion: AZA is safe and effective in the long-term in IBD. Effectiveness, tolerance, and compliance with AZA are well sustained beyond 5 years of usage and comparable between UC and CD.

Faecal microbiota composition in vegetarians: comparison with omnivores in a cohort of young women in southern India.

The effect of vegetarian diets on faecal microbiota has been explored largely through culture-based techniques. The present study compared the faecal microbiota of vegetarian and omnivorous young women in southern India. Faecal samples were obtained from thirty-two lacto-vegetarian and twenty-four omnivorous young adult women from a similar social and economic background. Macronutrient intake and anthropometric data were collected. Faecal microbiota of interest was quantified by real-time PCR with SYBR Green using primers targeting 16S rRNA genes of groups, including: Clostridium coccoides group (Clostridium cluster XIVa), Roseburia spp.-Eubacterium rectale, Bacteroides--Prevotella group, Bifidobacterium genus, Lactobacillus group, Clostridium leptum group (Clostridium cluster IV), Faecalibacterium prausnitzii, Ruminococcus productus--C. coccoides, Butyrivibrio, Enterococcus species and Enterobacteriaceae. The groups were matched for age, socio-economic score and anthropometric indices. Intake of energy, complex carbohydrates and Ca were significantly higher in the omnivorous group. The faecal microbiota of the omnivorous group was enriched with Clostridium cluster XIVa bacteria, specifically Roseburia-E. rectale. The relative proportions of other microbial communities were similar in both groups. The butyryl-CoA CoA-transferase gene, associated with microbial butyrate production, was present in greater amounts in the faeces of omnivores, and the levels were highly correlated with Clostridium cluster XIVa and Roseburia-E. rectale abundance and to a lesser extent with Clostridium leptum and F. prausnitzii abundance and with crude fibre intake. Omnivores had an increased relative abundance of Clostridium cluster XIVa bacteria and butyryl-CoA CoA-transferase gene compared with vegetarians, but we were unable to identify the components of the diet responsible for this difference.

Distribution of celiac disease predisposing genes HLA-DQ2 and HLA-DQ8 in the native population of southern India.

BACKGROUND: Celiac disease (CD) is an intestinal inflammatory condition caused by the ingestion of gluten peptides in wheat and related grains in individuals carrying HLA-DQ2 and/or HLA-DQ8 genes. In comparison to HLA-DQ8, a higher HLA-DQ2 prevalence is reported in European population where wheat has been the staple food for thousands of years. In non-European population, this pattern of HLA-DQ CD-predisposing gene distribution has not always been found. The aim of this study was to evaluate the HLA-DQ2 and HLA-DQ8 distribution in the native low-gluten consuming southern Indian population. METHODS: Overall, 211 dried blood spots (DBS) were collected from native southern Indian individuals. HLA-DQ characterization and the determination of homozygous/heterozygous status were performed using commercially available HLA-DQ typing kits. RESULTS: Of 211 collected DBS, 88 (42%, 95% CI: 36-48) were positive for HLA-DQ2 and/or HLA-DQ8 heterodimers. Overall, 40 (19%, 95% CI: 14-24) samples typed positive for HLA-DQ2 and 48 (23%, 95% CI: 18-28) typed positive for HLA-DQ8 genotypes. Of 40 HLA-DQ2-positive individuals, only one subject tested homozygous for the DQB1*02 allele. CONCLUSIONS: In the southern Indian native general population, the prevalence of HLA-DQ8 is higher in comparison to HLA-DQ2 prevalence. This finding could be related to the delayed introduction of wheat in the diet of the southern Indian population.

Endoscopic Stone Extraction followed by Laparoscopic Cholecystectomy in Tandem for Concomitant Cholelithiasis and Choledocholithiasis: A Prospective Study.

BACKGROUND: Single-session endoscopic stone extraction (ESE) and laparoscopic cholecystectomy (LC) has the best outcome in managing concomitant cholelithiasis (gallstone disease [GSD]) and choledocholithiasis (common bile duct stone [CBDS]). Traditional rendezvous technique with an intraoperative cholangiogram is associated with various technical (bowel distention, frozen Calot's triangle, limitation of intraoperative cholangiogram and so on) and logistical difficulties (lack of trained personnel and equipment for ESE in the operating room). We modified our approach of ESE-LC (tandem ESE-LC) to study the safety of the approach and overcome these disadvantages of the traditional rendezvous approach. METHODS: A prospective study of patients with GSD and suspected CBDS from January 2017 to December 2019 was conducted. Tandem ESE-LC involves ESE and LC under the same general anaesthesia in a single day, while ESE is performed in the endoscopic suite using carbon dioxide insufflation, a balloon/basket was used for achieving bile duct clearance and the same was confirmed with an occlusion cholangiogram. Patients were then shifted to the operating room for LC. The primary outcome included bile duct clearance and safety of the procedure. RESULTS: Of 56 patients assessed for eligibility, 42 were included in the study (median age: 53 years, 25 [60%] women). Biliary colic was the most common presenting symptom (n = 24, 57%), followed by acute cholecystitis (n = 11, 26%). The median number of stones and stone size was 1 (1-6) and 4 mm (3-10), respectively. All patients had successful bile duct clearance. Stenting was performed in 5 (12%) patients. Intraoperatively, Calot's dissection was difficult and frozen in 10 and 11 patients respectively. The cystic duct was short and wide in 13 (31%) patients. Subtotal cholecystectomy was performed in 6 (14%) patients. The median duration of postprocedural hospital stay was 1 (0-13) day. Three patients had tandem ESE-LC on a day-care basis. One patient had post-endoscopic retrograde cholangiopancretography pancreatitis, and another required percutaneous drainage for gall bladder fossa collection. No patient had retained CBDS at a median follow-up of 18 (3-28) months. CONCLUSION: Tandem ESE-LC is safe and effective method in managing concomitant GSD and CBDS.

Effect of yoghurt containing Bifidobacterium lactis Bb12® on faecal excretion of secretory immunoglobulin A and human beta-defensin 2 in healthy adult volunteers.

BACKGROUND: Probiotics are used to provide health benefits. The present study tested the effect of a probiotic yoghurt on faecal output of beta-defensin and immunoglobulin A in a group of young healthy women eating a defined diet. FINDINGS: 26 women aged 18-21 (median 19) years residing in a hostel were given 200 ml normal yoghurt every day for a week, followed by probiotic yoghurt containing Bifidobacterium lactis Bb12® (109 in 200 ml) for three weeks, followed again by normal yoghurt for four weeks. Stool samples were collected at 0, 4 and 8 weeks and assayed for immunoglobulin A and human beta-defensin-2 by ELISA. All participants tolerated both normal and probiotic yoghurt well. Human beta-defensin-2 levels in faeces were not altered during the course of the study. On the other hand, compared to the basal sample, faecal IgA increased during probiotic feeding (P = 0.0184) and returned to normal after cessation of probiotic yoghurt intake. CONCLUSIONS: Bifidobacterium lactis Bb12® increased secretory IgA output in faeces. This property may explain the ability of probiotics to prevent gastrointestinal and lower respiratory tract infections.

Human Leukocyte Antigen DQ (HLA-DQ) genotypes and haplotypes and their association with phenotype in patients with celiac disease in India.

BACKGROUND AND AIM: Human Leukocyte Antigen DQ (HLA-DQ) genotypes play a permissive role in the genesis of celiac disease (CeD). In this case-control study, we used next-generation sequencing to determine HLA-DQA1 and ~DQB1 genotypes and haplotypes associated with CeD in Indian patients. METHODS: HLA-DQA1 and ~DQB1 loci were amplified, using long-range polymerase chain reaction (PCR), from DNA of 259 patients with symptomatic CeD (160 typical and 99 atypical), 45 asymptomatic CeD, 96 potential CeD, and 300 healthy adults. Amplicons were fragmented and sequenced on the Illumina platform, and alleles and haplotypes were assigned by matching against the HLA-international ImMunoGeneTics (IMGT) database. RESULTS: HLA-DQA1*05:01 (odds ratio [OR] 8.39, 95% confidence interval [CI] 5.64-12.47) and HLA-DQB1*02:01 (OR 8.59, 95% CI 5.75-12.83) were the genotypes that showed a risk association with symptomatic CeD. Among the haplotypes, HLA-DQA1*05:01 ~ HLA-DQB1*02:01 (OR 8.56, 95% CI 5.67-13.19) showed a strong risk association with symptomatic CeD. When comparing symptomatic CeD with subclinical forms (asymptomatic and potential) CeD, HLA-DQA1*05:01 ~ HLA-DQB1*02:01 (OR 2.34, 95% CI 1.61-3.43) was significantly associated with risk of symptomatic disease. The strength of association between the HLA-DQA1*05:01 ~ HLA-DQB1*02:01 haplotype and the CeD phenotype showed a gradient in the order typical > atypical > asymptomatic > potential CeD. Genotypes consistent with expression of HLA DQ2 and/or 8 were noted in 128 (80%) typical, 73 atypical (74%), 27 (60%) asymptomatic, and 52 (54%) potential CeD participants. CONCLUSION: HLA-DQA1*05:01 ~ HLA-DQB1*02:01 (haplotype DQ2.5) showed a very strong risk association with symptomatic CeD in Indian patients. The strength of association showed a gradient of increase from potential to typical CeD, coinciding with a phenotypic change in the celiac iceberg.

Quantitative differences in intestinal Faecalibacterium prausnitzii in obese Indian children.

Gut bacteria contribute to energy conservation in man through their ability to ferment unabsorbed carbohydrate. The present study examined the composition of predominant faecal microbiota in obese and non-obese children. The participants (n 28) aged 11-14 years provided fresh faecal samples and completed a dietary survey consisting of 24 h diet recall and a FFQ of commonly used foods taken over the previous 3 months. Faecal bacteria were quantitated by real-time PCR using primers targeted at 16S rDNA. Of the participants, fifteen (seven female) were obese, with median BMI-for-age at the 99th percentile (range 97 to>99) while thirteen participants (seven female) were normal weight, with median BMI-for age being at the 50th percentile (range 1-85). Consumption of energy, carbohydrates, fat and protein was not significantly different between the obese and non-obese participants. There was no significant difference between the two groups in faecal levels of Bacteroides-Prevotella, Bifidobacterium species, Lactobacillus acidophilus group or Eubacterium rectale. Levels of Faecalibacterium prausnitzii were significantly higher in obese children than in non-obese participants (P = 0.0253). We concluded that the finding of increased numbers of F. prausnitzii in the faeces of obese children in south India adds to the growing information on alterations in faecal microbiota in obesity.

Low levels of faecal lactobacilli in women with iron-deficiency anaemia in south India.

Fe deficiency in women contributes significantly to maternal and child morbidity in India. The intestinal bacterial flora may facilitate absorption of Fe from the caecum and proximal colon. The present study investigated the possibility that intestinal microbiota of anaemic young women may differ from that of women with normal Hb levels. The microbiota was quantified by real-time PCR in faeces of eight anaemic (Hb ≤ 100 g/l) and twenty-six normohaemic (Hb ≥ 120 g/l) women aged 18-25 years. Sequences of 16S ribosomal DNA (rDNA) specific to Bifidobacterium genus, Lactobacillus acidophilus group, Bacteroides-Prevotella-Porphyromonas group, Clostridium leptum group and Eubacterium rectale were amplified and expressed (as relative difference) relative to the universally conserved bacterial 16S rDNA sequences. Dietary intakes of energy, carbohydrate, fibre and Fe were ascertained by maintenance of a diet diary for a week. Faecal lactobacilli were significantly lower in anaemic women (median 6.6 × 10(-8), relative difference compared with total bacteria) than in the reference group (2.9 × 10(-6); P = 0.001, unpaired t test with logarithmic transformation). There was no difference between the two groups with respect to any of the other bacteria that were examined. Intakes of energy, carbohydrate, fibre, Fe and milk were similar in both the groups. Fe deficiency in young women in south India was associated with low levels of lactobacilli in the faeces. The relationship between lactobacilli and Fe deficiency needs to be explored further.

Longest form of CCTG microsatellite repeat in the promoter of the CD2BP1/PSTPIP1 gene is associated with aseptic abscesses and with Crohn disease in French patients.

PURPOSE: Aseptic abscesses syndrome (AA) is an inflammatory disease in which non-infectious deep abscesses develop; these respond quickly to corticosteroids. AA is associated with Crohn disease (CD) in 57% of cases and with neutrophilic dermatosis (ND) in 20%. Pyoderma gangrenosum is usually a sporadic ND. A hereditary autosomal dominant syndromic kind of pyoderma gangrenosum, the PAPA syndrome, is linked to mutations in the CD2BP1/PSTPIP1 gene. We systematically screened this gene in French AA patients. RESULTS: One microsatellite (CCTG)n with 3 alleles was identified in the promoter. The longest form (CCTG)7 was significantly more frequent in AA patients than in French controls (P = 0.0154). We also found an association of the (CCTG)7 allele with CD in French patients (P = 0.0351). This association was not found in a sample of Indian patients. CONCLUSIONS: The CCTG repeat in the PSTPIP1 promoter may play a role in the pathogenesis of AA and of CD. Further investigations are required to demonstrate the possible modulation of gene expression by the (CCTG)n motif.

Faecal bifidobacteria in Indian neonates & the effect of asymptomatic rotavirus infection during the first month of life.

BACKGROUND AND OBJECTIVES: Bifidobacteria colonize the gut after the first week of life and remain an important component of the gut microbiota in infancy. This study was carried out to characterize the diversity and number of bifidobacteria colonizing the gut in Indian neonates and to investigate whether asymptomatic infection with rotavirus in the first month of life affected gut colonization by bifidobacteria. METHODS: DNA was isolated from faeces of 14 term-born neonates who were under surveillance for rotavirus infection. Bacterial and bifidobacterial diversity was evaluated by temporal temperature gradient electrophoresis (TTGE) of 16S rDNA amplified using total bacteria and bifidobacteria-specific primers. Real time PCR, targeting 16S rDNA, was used to quantitate faecal bifidobacteria and enterobacteria. RESULTS: TTGE of conserved bacterial 16S rDNA showed 3 dominant bands of which Escherichia coli (family Enterobacteriaceae) and Bifidobacterium (family Bifidobacteriaceae) were constant. TTGE of Bifidobacterium genus-specific DNA showed a single band in all neonates identified by sequencing as Bifidobacterium longum subsp. infantis. Faecal bifidobacterial counts (log 10 cfu/g faeces) ranged from 6.1 to 9.3 and enterobacterial counts from 6.3 to 9.5. Neonates without and with rotavirus infection in the first week of life did not show significant differences in the median count of bifidobacteria (log 10 count 7.48 vs. 7.41) or enterobacteria (log 10 count 8.79 vs. 7.92). INTERPRETATION AND CONCLUSIONS: B. longum subsp. infantis was the sole bifidobacterial species colonizing the gut of Indian neonates. Asymptomatic rotavirus infection in the first month of life was not associated with alteration in faecal bifidobacteria or enterobacteria.

Frequency of HLA celiac disease risk alleles and haplotypes in healthy adults in Tamil Nadu.

Celiac disease (CeD) occurs only in individuals who are able to express human leukocyte antigens (HLA) DQ2 or DQ8, and these are expressed in nearly a third of healthy people in the West. As the disease is very uncommon in Tamil Nadu, we evaluated the possibility that the relevant genes are infrequent in this population. Four hundred healthy adults without any gastrointestinal abnormalities were recruited from Vellore district of Tamil Nadu. Genomic DNA was extracted from venous blood and amplified by PCR using the allele-specific primers for the following alleles-DQA1*0201, 0301, and 0501 and DQB1*02, 0201, and 0302, which determine the CeD risk haplotypes. Among the 400 healthy adults, the presence of DQ2.5 (DQB1*0201-DQA1*0501) and DQ2.2 (DQB1*02-DQA1*0201) haplotypes was found in 8.25% and 14.25%, respectively. DQ8 (DQB1*0302-DQA1*0301) haplotype was identified in only 3% of healthy individuals. Overall, approximately a quarter of healthy adults in Tamil Nadu had the potential CeD risk haplotypes of HLA DQ2.5, DQ2.2, and DQ8.