Modern-Day Therapeutics and Ongoing Clinical Trials against Type 2 Diabetes Mellitus: A Narrative Review.

OBJECTIVES: Diabetes Mellitus (DM) is a global health concern that affects millions of people globally. The present review aims to narrate the clinical guidelines and therapeutic interventions for Type 2 Diabetes Mellitus (T2DM) patients. Furthermore, the present work summarizes the ongoing phase 1/2/3 and clinical trials against T2DM. METHODS: A meticulous and comprehensive literature review was performed using various databases, such as PubMed, MEDLINE, Clinical trials database (https://clinicaltrials.gov/), and Google Scholar, to include various clinical trials and therapeutic interventions against T2DM. RESULTS: Based on our findings, we concluded that most T2DM-associated clinical trials are interventional. Anti-diabetic therapeutics, including insulin, metformin, Dipeptidyl Peptidase-4 (DPP-4) inhibitors, Glucagon-Like Peptide-1 Receptor Agonists (GLP-1RAs), and Sodium- Glucose cotransporter-2 (SGLT-2) inhibitors are frontline therapeutics being clinically investigated. Currently, the therapeutics in phase IV clinical trials are mostly SGLT-2 inhibitors, implicating their critical contribution to the clinical management of T2DM. CONCLUSION: Despite the success of T2DM treatments, a surge in innovative treatment options to reduce diabetic consequences and improve glycemic control is currently ongoing. More emphasis needs to be on exploring novel targeted drug candidates that can offer more sustained glycemic control.

Genetic variability of histidine-rich protein 2 repeat sequences: Misleading factor in true determination of Plasmodium falciparum in different population.

PURPOSE: Genetically diverse parasites enhances resistance against antimalarials, vaccines and host immune responses. The present study was designed to evaluate the role played by Plasmodium falciparum genetic diversity in predicting the real world malarial population. METHODS: Initially, the incidence pattern of all four northern Indian malarial species was examined using 18S rRNA gene and performed principal component analysis (PCA) based on frequencies of Plasmodium species. Consequently, genetic variance of Plasmodium falciparum histidine-rich protein-2 (Pfhrp2) gene among different malarial populations were compared using phylogenetic analysis. Multi-dimensional scaling was performed to assess genetic similarities and distances among studied populations. RESULTS: Of total 2168 patients screened, 561 patients with fever of unknown origin were included. 18S rRNA and Pfhrp2 genes were amplified in 78 and 45 samples, respectively. Among them 13.9%(78/561) patients had Plasmodium infection. Infections by P. falciparum, P. vivax and mixed infections were diagnosed among 47(60.2%) and 28(35.9%) and 3(3.8%) patients, respectively. We found eight types of Pfhrp2 amino acid sequence repeats among northern Indian population. The PCA findings were in line with genetic diversity and phylogenetic data. Temporal analysis showed the proportion of total diversity present in total subpopulation (ΔS/ΔT) was maximum for P. falciparum. CONCLUSIONS: Higher incidence of Pfhrp2 sequence variation through genetic recombination among multiple strains during sexual reproduction is potentially correlated with high transmission activity. This sequence variation might alter RDT detection sensitivities for different parasites by modulating the structure and frequency of antigenic epitopes.

Emerging trends in gastrointestinal cancers: Targeting developmental pathways in carcinogenesis and tumor progression.

Gastrointestinal carcinomas are a group of cancers associated with the digestive system and its accessory organs. The most prevalent cancers related to the gastrointestinal tract are colorectal, gall bladder, gastric, hepatocellular, and esophageal cancers, respectively. Molecular aberrations in different signaling pathways, such as signal transduction systems or developmental pathways are the chief triggering mechanisms in different cancers Though a massive advancement in diagnostic and therapeutic interventions results in improved survival of patients with gastrointestinal cancer; the lower malignancy stages of these carcinomas are comparatively asymptomatic. Various gastrointestinal-related cancers are detected at advanced stages, leading to deplorable prognoses and increased rates of recurrence. Recent molecular studies have elucidated the imperative roles of several signaling pathways, namely Wnt, Hedgehog, and Notch signaling pathways, play in the progression, therapeutic responsiveness, and metastasis of gastrointestinal-related cancers. This book chapter gives an interesting update on recent findings on the involvement of developmental signaling pathways their mechanistic insight in gastrointestinalcancer. Subsequently, evidences supporting the exploration of gastrointestinal cancer related molecular mechanisms have also been discussed for developing novel therapeutic strategies against these debilitating carcinomas.

Clinicopathological and prognostic significance of VEGF, PDGF-B, and HER2/neu expression in gallbladder cancer.

AIM: Gallbladder cancer (GBC) is usually diagnosed in advanced stages with poor survival. The molecular mechanisms of GBC still remain unexplored. Several angiogenesis factors play a pivotal role in tumor progression. We aimed to study the expression of VEGF, PDGF-B, and human epidermal growth factor receptor 2 (HER2/neu) and its association with clinicopathological features and survival in GBC. MATERIALS AND METHODS: VEGF, PDGF-B, and HER2/neu expression was studied by immunohistochemistry (IHC) after histological evaluation in 91 GBC cases. The relationship between these markers and clinicopathological features and survival was explained through the Cox regression model and Kaplan-Meier method. RESULTS: VEGF, PDGF-B, and HER2/neu overexpressed in 45, 79, and 68% GBC cases, respectively. VEGF was significantly overexpressed in GBC without gall stones (GS) (p = 0.007) and with moderately and poorly differentiated tumors (p = 0.012). HER2/neu was significantly overexpressed in GBC with GS (p = 0.022). Median overall survival (OS) was 39 months (95% CI: 23-55). In univariate analysis, histological type (adenocarcinoma and papillary) vs. others (signet ring/mucinous/adenosquamous) (p = 0.004), depth of tumor infiltration (p = 0.017), distant metastasis (p = 0.012), and adjuvant therapies (chemotherapy/radiotherapy) (p = 0.083) were associated with poor prognosis. Multivariate survival analysis showed histological type (p = 0.004) and distant metastasis (p = 0.032) to be independent prognostic factors for OS. Histological type (p = 0.002), distant metastasis (p = 0.003), and depth of tumor infiltration (T3-T4) (p = 0.012) showed poor median survival. Poor survival was seen in VEGF and HER2/neu positive cases. CONCLUSION: Overexpression of VEGF, PDGF-B, and HER2/neu might be possible prognostic biomarkers in GBC. Poor survival of VEGF and HER2/neu positive cases indicates the possibilities of using their blockers as therapeutic agents.

High therapeutic efficacy of 5-Fluorouracil-loaded exosomes against colon cancer cells.

The successful chemotherapeutic regime required for the clinical management of different cancers largely depends on the efficient drug delivery within the cancer cells. Exosomes have emerged as an enticing candidate for exploring their role as delivery vehicles. Exosomes are reported to be intrinsically nanosized vesicles competent for efficient delivery across the cellular membrane. In the present study, we assessed the feasibility of an autologous exosome-based drug delivery platform for delivering 5-Fluorouracil (5-FU) against human colon cancer HCT116 cells. Autologous exosomes have shown probable tropism toward the tumor microenvironment, which makes them the most competitive vehicle for drug delivery. It was observed that the autologous exosomes loaded with 5-FU showed an enhanced rate of drug release under acidic conditions. The result of the cell viability assay showed that treatment of 5-FU-loaded exosomes (equivalent to 5 µg 5-FU) resulted in enhanced cytotoxic effect in HCT116 cells as compared to an equivalent amount of free 5-FU (5 µg), which elucidated the efficient delivery of the 5-FU by exosomes inside the cancer cells. Subsequently, 5-FU-loaded exosomes led to increased nuclear condensation and fragmentation along with increased ROS production. In addition, 5-FU-loaded exosomes caused enhanced dissipation of mitochondrial membrane potential and caspase-3 activation, resulting in increased apoptosis induction. Our study also revealed that 5-FU-loaded exosomes upsurged the arrest in the cell cycle at the G0/G1 stage in HCT-116 cells and it was found to be associated with decreased CDK4 and Cyclin D1 expression concomitantly with the upregulation of CDK inhibitor, p21Cip1 expression. Thus, the findings from the present study highlight the advantages of autologous exosomes as a natural drug carrier which could efficiently deliver chemotherapeutic drugs to cancer cells.

A New Perspective on Partial Nail Avulsion: Surgical Pearl.

Ingrown nail or onychocryptosis is a common and prevalent condition associated with pain and discomfort resulting from recurrent inflammation. It is further categorized into 3 grades on the basis of severity as per classification by Heifetz and Mogensen, grade 1 can be easily managed with medical treatment; whereas grades 2 and 3 often requires surgical treatment; the most common surgical technique employed for ingrown nail is the simple nail avulsion by using a nail clipper. we have observed that due to the force of the nail clipper small amount of detachment in between nail plate and nail bed in addition to longer downtime post-procedure, so we proposed a new surgical modification of nail avulsion by using 11 no. surgical blade instead of nail clippers leading to very less trauma to nail bed and fine post-procedure outcomes.

Eosinophilic Granulomatosis with Polyangiitis.

Eosinophilic granulomatosis with polyangiitis also known as Churg-Strauss syndrome or allergic granulomatosis and angiitis is an extremely rare systemic necrotizing vasculitis that affects small-to-medium-sized vessels. Here, we report a case of a 58-year-old man presenting with painful swelling of bilateral lower limbs with multiple well-defined erosions on lower legs and dorsum of the foot with a few of them showing brownish crusts and with slight watery discharge and a few with raw areas. The patient is a known case of bronchial asthma. Histopathology of foot and face lesion shows inflammatory cell infiltrate predominantly comprising of eosinophils, small- and medium-sized blood vessels are thickened. P-antineutrophil cytoplasmic antibody positivity was seen. Thus, on the basis of positive findings which satisfy the criteria for eosinophilic granulomatosis with polyangiitis, we diagnosed this as a case of eosinophilic granulomatosis with polyangiitis, and for rarity of this case, we would like to report it.

Surgical Treatment in Hidradenitis Suppurativa.

Hidradenitis suppurativa (HS) is a chronic, progressive inflammatory disorder of follicular occlusion with pubertal onset that presents as painful inflammatory nodules, sinus tracts, and tunnelling in apocrine-gland-rich areas, such as the axilla, groin, lower back, and buttocks. The disease course is complicated by contractures, keloids, and immobility and is often associated with a low quality of life. It is considered a disorder of follicular occlusion with secondary inflammation, though the exact cause is not known. Management can often be unsatisfactory and challenging due to the chronic nature of the disease and its adverse impact on the quality of life. A multidisciplinary approach is key to prompt optimal disease control. The early stages can be managed with medical treatment, but the advanced stages most likely require surgical intervention. Various surgical options are available, depending upon disease severity and patient preference. In this review an evidence-based outline of surgical options for the treatment of HS are discussed. Case reports, case series, cohort studies, case-control studies, and Randomized Clinical Trials (RCT)s available in medical databases regarding surgical options used in the treatment of HS were considered for the review presented in a narrative manner in this article.

Treatment Update of Port-Wine Stain: A Narrative Review.

BACKGROUND: Port-wine stain (PWS) is a congenital vascular malformation affecting 0.3–0.5% of normal population. These characteristic lesions arise due to the interplay of vascular, neural, and genetic factors. Treatment options include lasers, cosmetic tattooing, electrotherapy, cryosurgery, derma-abrasion, and skin grafting; however, none of these treatment alternatives appears to be satisfactory and is unable to provide consistent, satisfactory responses or even complete cures. Currently, laser is the treatment of choice, as it is comparatively safe and more effective than other procedures. The most commonly used modality is pulsed dye laser (PDL). The literature research includes peer-reviewed articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) to January 2020 and reference lists of respective articles. Only articles published in English language were included. J Drugs Dermatol. 20(5): doi:10.36849/JDD.5005.

Prevalence of acne vulgaris and its clinico-epidemiological pattern in adult patients: Results of a prospective, observational study.

BACKGROUND: Acne is a common disorder in adolescents. The prevalence of acne in adults is also increasing. There are only a few Indian studies on the prevalence and clinical features of adult acne. AIMS: To evaluate the prevalence and possible etiological and aggravating factors of acne in adult population. METHODS: Adult patients more than 25 years with acne were enrolled, and detailed history and examination were recorded. Type of acne, age, gender, area of involvement, and associated factors were noted. RESULTS: Out of 24,056 adult patients, 180 had acne, with the prevalence of 0.74%. Mean age of patients with acne was 30.1 years. A total of 81.7% patients with acne were female and 68.3% had persistent type of acne. Inflammatory papular acne (72.8%) was the most common type of acne in our study population. Cheek (85%) was the predominant site of involvement; 62.8% patients developed scarring. Underlying chronic stress was present in 23.9% and family history of acne in 60.6%. A total of 43.5% patients reported aggravation with cosmetics and 42.8% provided history of oily and high glycemic food conduction. Premenstrual flare and hirsutism were seen in 61.9% and 16.3% female patients, respectively. CONCLUSION: Acne is more common in people with 25-35 years of age with female preponderance and a gradual decline in the prevalence is seen thereafter. Inflammatory nature is more common with cheeks being commonest site of affection. Facial scarring is more common that emphasizes the importance of early and adequate intervention.

Roles of Salmonella typhi and Salmonella paratyphi in Gallbladder Cancer Development.

BACKGROUND: Typhoid (Salmonella typhi and paratyphi) carriers and gall bladder cancer (GBC) are endemic in northern India. Results of previous studies about association of typhoid carriers with GBC are inconsistent. We studied antibodies against Salmonella typhi and paratyphi in serum samples of patients with GBC. METHODS: We performed modified Widal test for antibodies against Salmonella typhi (Vi and O) and Salmonella paratyphi (AO and BO) antigens in patients with GBC (n=100), xanthogranulomatous cholecystitis (XGC, n=24), chronic cholecystitis (CC, n=200) and healthy controls (HC, n=200). RESULTS: Serum antibodies against Salmonella were more frequently positive in GBC (22%) and XGC (29%), particularly in males in age ≥50 years (GBC: 47% and XGC: 50%) vs. HC (0) (p <0.01). Vi antibody was more common in GBC (13%, OR:9.8) and XGC (8%, OR:5.9) than HC (2%). O antibody was more common in GBC (8%, OR: 8.6) and XGC (8%, OR: 9.0) than HC (1%). O antibody was also more common in males with GBC (12%) than CC (1%) and HC (1%) (P=0.02 and p <0.001, respectively). AO (6%) and BO (4%) antibodies were detected in GBC, particularly in males, than HC (0), (p <0.01). Salmonella antibodies were more frequent in GBC with GS than those without GS (50% vs. 20%, OR=3.94, P=0.01). CONCLUSIONS: Salmonella carrier state was more common in GBC and XGC, particularly in elderly males than HC. The Vi antibody was more common in GBC and XGC than HC. Salmonella infection was more common in GBC with GS than those without GS.

Bile duct injury during laparoscopic cholecystectomy: An Indian e-survey.

BACKGROUNDS/AIMS: In the absence of national registry of laparoscopic cholecystectomy (LC) or its complications, it is impossible to determine incidence of bile duct injury (BDI) in India. We conducted an e-survey among practicing surgeons to determine prevalence and management patterns of BDI in India. Our hypothesis was that majority of surgeons would have experienced a BDI during LC despite large experience and that most surgeons who have a BDI tend to manage it themselves. METHODS: An 18-question e-survey of practicing laparoscopic surgeons in India was done. RESULTS: 278/727 (38%) surgeons responded. 240/278 (86%) respondents admitted to a BDI during LC and 179/230 (78%) affirmed to more than one BDI. A total of 728 BDIs were reported. 36/230 (15%) respondents experienced their first BDI even after ＞10 years of practice and 40% had their first BDI even after having performed ＞100 LCs. 161/201 (80%) of the respondents decided to manage the BDI themselves, including 56/99 (57%) non-biliary surgeons and 44/82 (54%) surgeons working in non-biliary center. 37/201 (18%) respondents admitted to having a mortality arising out of a BDI; the mortality rate of BDI was 37/728 (5%) in this survey. Only 13/201 (6%) respondents have experienced a medico-legal case related to a BDI during LC. CONCLUSIONS: Prevalence of BDI is high in India and occurs despite adequate experience and volume. Even inexperienced non-biliary surgeons working in non-biliary centers attempt to repair the BDI themselves. BDI is associated with significant mortality but litigation rates are fortunately low in India.

Emerging metronidazole resistance in Bacteroides spp. and its association with the nim gene: a study from North India.

OBJECTIVES: Bacteroides spp. are anaerobic resident intestinal flora but are also known to cause severe morbidity. They are resistant to a wide variety of antimicrobial agents, including metronidazole, which has been shown to be associated with specific nitroimidazole (nim) resistance genes. Metronidazole resistance is emerging worldwide, although presently it remains at ca. 5%. This study aimed to determine the metronidazole susceptibility and distribution of nim genes in Bacteroides spp. clinical isolates in India. The relationship among strains harbouring nim genes and their susceptibility to metronidazole was also analysed. METHODS: A total of 42 Bacteroides spp. clinical isolates were identified using an advanced MALDI-TOF system. Minimum inhibitory concentrations (MICs) for metronidazole were determined by the agar dilution method. Bacterial DNA was extracted and was subjected to nim gene PCR and the amplified PCR products were sequenced to determine the prevalent nim types. RESULTS: Bacteroides fragilis was the most common isolate (64%) among all Bacteroides spp. isolates. Among the total 42 clinical Bacteroides spp. isolates, 29 (69%) were susceptible and 13 (31%) were resistant to metronidazole by the agar dilution method. nim gene PCR performed on 38 isolates showed positivity in 20 isolates (53%), of which 12 had high metronidazole MICs (χ2 test, P<0.005). On sequencing, these nim genes were most closely related to nimE type. CONCLUSION: Resistance to metronidazole is consistently emerging worldwide. There is a significant association of the nim gene with metronidazole resistance. Periodic surveillance is needed to detect geographic and temporal trends in nim gene prevalence.

Expression of Toll-like Receptors, Pro-, and Anti-inflammatory Cytokines in Relation to Gut Microbiota in Irritable Bowel Syndrome: The Evidence for Its Micro-organic Basis.

BACKGROUND/AIMS: A Subset of patients with irritable bowel syndrome (IBS) may have mild inflammation due to immune activation. Toll-like receptors (TLRs) and cytokines may cause intestinal inflammation. We studied their expression in relation to gut microbiota. METHODS: Expression of TLRs and cytokines was assessed in 47 IBS patients (Rome III) and 25 controls using quantitative real-time polymerase chain reaction. Immunohistochemistry was further performed to confirm the expression of TLR-4 and TLR-5. RESULTS: Of 47 patients with IBS, 20 had constipation (IBS-C), 20 diarrhea (IBS-D), and 7 unclassified (IBS-U). The mRNA levels of TLR-4 and TLR-5 were up-regulated in IBS patients than controls (P = 0.013 and P < 0.001, respectively). Expression of TLR-4 and TLR-5 at protein level was 4.2-folds and 6.6-folds higher in IBS-D than controls. The mRNA levels of IL-6 (P = 0.003), C-X-C motif chemokine ligand 11 (CXCL-11) (P < 0.001) and C-X-C motif chemokine receptor 3 (CXCR-3) (P < 0.001) were higher among IBS patients than controls. Expression of IL-6 (P = 0.002), CXCL-11 (P < 0.001), and CXCR-3 (P < 0.001) were up-regulated and IL-10 (P = 0.012) was down-regulated in IBS-D patients than controls. Positive correlation was seen between TLR-4 and IL-6 (P = 0.043), CXCR-3, and CXCL-11 (P = 0.047), and IL-6 and CXCR-3 (P = 0.003). Stool frequency per week showed positive correlation with mRNA levels of TLR-4 (P = 0.016) and CXCR-3 (P = 0.005), but inversely correlated with IL-10 (P = 0.002). Copy number of Lactobacillus (P = 0.045) and Bifidobacterium (P = 0.011) showed correlation with IL-10 in IBS-C, while Gram-positive (P = 0.031) and Gram-negative bacteria (P = 0.010) showed correlation with CXCL-11 in IBS-D patients. CONCLUSIONS: Altered immune activation in response to dysbiotic microbiota may promote intestinal inflammation in a subset of patients with IBS.

Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy.

The pathogenesis of irritable bowel syndrome (IBS), once thought to be largely psychogenic in origin, is now understood to be multifactorial. One of the reasons for this paradigm shift is the realization that gut dysbiosis, including small intestinal bacterial overgrowth (SIBO), causes IBS symptoms. Between 4% and 78% of patients with IBS and 1% and 40% of controls have SIBO; such wide variations in prevalence might result from population differences, IBS diagnostic criteria, and, most importantly, methods to diagnose SIBO. Although quantitative jejunal aspirate culture is considered the gold standard for the diagnosis of SIBO, noninvasive hydrogen breath tests have been popular. Although the glucose hydrogen breath test is highly specific, its sensitivity is low; in contrast, the early-peak criteria in the lactulose hydrogen breath test are highly nonspecific. Female gender, older age, diarrhea-predominant IBS, bloating and flatulence, proton pump inhibitor and narcotic intake, and low hemoglobin are associated with SIBO among IBS patients. Several therapeutic trials targeting gut microbes using antibiotics and probiotics have further demonstrated that not all symptoms in patients with IBS originate in the brain but rather in the gut, providing support for the micro-organic basis of IBS. A recent proof-of-concept study showing the high frequency of symptom improvement in patients with IBS with SIBO further supports this hypothesis.

Interleukin-10: A Compelling Therapeutic Target in Patients With Irritable Bowel Syndrome.

PURPOSE: Pro- and antiinflammatory cytokines are important modulators of the immune response and play a major role in conditions of intestinal inflammation, such as irritable bowel syndrome (IBS). Cytokine production is regulated genetically, and imbalances in cytokine secretion may affect disease susceptibility and clinical outcomes of various conditions. There is a rapidly growing body of evidence to support an etiologic role for gastrointestinal infection and the associated immune activation in the development of postinfectious IBS. Other factors such as psychological stress, anxiety, and depression may likely be involved in the altered profiles of pro- and antiinflammatory cytokines that lead to chronic IBS. METHODS: We searched the literature using PubMed, MEDLINE, and Google Scholar with related key terms and prepared this review article on that basis. FINDINGS: Interleukin (IL)-10 is a regulatory cytokine that inhibits both antigen presentation and the release of proinflammatory cytokines. Therefore, it is proposed as a potent antiinflammatory biological therapy for IBS. IMPLICATIONS: Recently, a strong interest in the therapeutic potential of IL-10 for IBS has developed. The diverse roles of IL-10 in IBS are reviewed here. We conducted an in-depth review on IL-10 and IBS to address this question. Future studies of IL-10 may provide new insights into IBS therapy.

Frequency, diagnostic performance of coproantigen detection and genotyping of the Giardia among patients referred to a multi-level teaching hospital in northern India.

Giardiasis, a common gastrointestinal parasitic infection in tropics, is diagnosed on stool microscopy (gold standard); however, its sensitivity is low due to intermittent fecal shedding. Coproantigen detection (ELISA) is useful but requires further evaluation. We aimed to study: (a) detection of Giardia by stool microscopy and/or coproantigen, (b) diagnostic performance of fecal antigen detection and microscopy, and c) genotypic characterization of G. lamblia using PCR specific for triose phosphate isomerase (tpi) gene. Stool samples from 2992 patients were examined by microscopy from March 2013 to March 2015 in a multi level teaching hospital in northern India. Giardia coproantigen detection was performed by ELISA in a subset of patients. Genetic characterization of G. lamblia was performed by PCR targeting tpi gene in a subset of microscopy positive stool samples. Of 2992 patients, 132 (4.4%) had Giardia by microscopy (cyst/trophozoite) and/or ELISA. ELISA was performed in 264 patients; of them, 127 were positive by microscopy. Sensitivity, specificity, positive and negative predictive values of ELISA were 91, 91, 94, and 91%, respectively, using microscopy as a gold standard. PCR was performed in 116 randomly selected samples having Giardia using tpi gene. Assemblages A and B were found among 44 (38%) and 72 (62%) patients, respectively. Assemblage B was more often associated with malnutrition and loss of appetite than A (48/72 [67%] vs. 21/44 [48%], P = 0.044 and 17/72 [24%] vs. 14/44 [32%], P = 0.019). We conclude that 4.4% of studied population had giardiasis. Fecal antigen is a useful method for diagnosis and assemblage B is the most common genotype.

Irritable Bowel Syndrome, Particularly the Constipation-Predominant Form, Involves an Increase in Methanobrevibacter smithii, Which Is Associated with Higher Methane Production.

BACKGROUND/AIMS: Because Methanobrevibacter smithii produces methane, delaying gut transit, we evaluated M. smithii loads in irritable bowel syndrome (IBS) patients and healthy controls (HC). METHODS: Quantitative real-time polymerase chain reaction for M. smithii was performed on the feces of 47 IBS patients (Rome III) and 30 HC. On the lactulose hydrogen breath test (LHBT, done for 25 IBS patients), a fasting methane result ≥10 ppm using 10 g of lactulose defined methane-producers. RESULTS: Of 47, 20 had constipation (IBS-C), 20 had diarrhea (IBS-D) and seven were not sub-typed. The M. smithii copy number was higher among IBS patients than HC (Log105.4, interquartile range [IQR; 3.2 to 6.3] vs 1.9 [0.0 to 3.4], p<0.001), particularly among IBS-C compared to IBS-D patients (Log106.1 [5.5 to 6.6] vs 3.4 [0.6 to 5.7], p=0.001); the copy number negatively correlated with the stool frequency (R=-0.420, p=0.003). The M. smithii copy number was higher among methane-producers than nonproducers (Log106.4, IQR [5.7 to 7.4] vs 4.1 [1.8 to 5.8], p=0.001). Using a receiver operating characteristic curve, the best cutoff for M. smithii among methane producers was Log106.0 (sensitivity, 64%; specificity, 86%; area under curve [AUC], 0.896). The AUC for breath methane correlated with the M. smithii copy number among methane producers (r=0.74, p=0.008). Abdominal bloating was more common among methane producers (n=9/11 [82%] vs 5/14 [36%], p=0.021). CONCLUSIONS: Patients with IBS, particularly IBS-C, had higher copy numbers of M. smithii than HC. On LHBT, breath methane levels correlated with M. smithii loads.