Human Gut Microbes Associated with Systolic Blood Pressure.

Emerging studies have revealed a strong link between the gut microbiome and several human diseases. Since human gut microbiome mirrors variations in lifestyle and environment, whether associations between disease conditions and gut microbiome are consistent across populations-particularly in communities practicing traditional subsistence strategies whose microbiomes differ markedly from industrialists-remains unknown. Cardiovascular diseases are the leading cause of mortality in India affecting 55 million people, and high blood pressure is one of the primary risk factors for cardiovascular diseases. We examined associations between gut microbiome and blood pressure along with 14 other variables associated with lifestyle, dietary habits, disease conditions, and clinical blood markers in the three Assamese populations. Our analysis reveals a robust link between the gut microbiome diversity and composition and systolic blood pressure. Moreover, several genera previously associated with hypertension in non-Indian populations were also associated with systolic blood pressure in this cohort and these genera were predictors of elevated blood pressure in these populations. These findings confer opportunities to design personalized, preventative, and targeted interventions harnessing the gut microbiome to tackle the burden of cardiovascular diseases in India.

Traditional rice beer depletes butyric acid-producing gut bacteria Faecalibacterium and Roseburia along with fecal butyrate levels in the ethnic groups of Northeast India.

Ethnicity, geography, and dietary habits are known to have dominant roles in modulating the gut microbiota. Two major ethnic groups Ahom and Bodo in the north-east of India consume traditionally prepared rice beer which contains various microbes and substances that promote the growth of such microbes, known as prebiotics. This study aimed to understand the effect of traditionally prepared rice beer on gut microbiota. A total of 134 (67 from each group) volunteers including non-drinkers and drinkers from three locations were recruited. Fecal and blood samples were collected to study fecal bacterial and metabolite profiles and biochemical markers, respectively. Amplicon 16S rRNA gene sequencing (region V3-V4) by next-generation sequencing showed similar alpha and beta diversities in both the ethnic groups. However, with rice beer consumption the abundance of Firmicutes, Bacteroidetes, Fusobacteria phyla was higher in the drinkers (p < 0.05) of Ahom whereas only Firmicutes were higher in Bodo ethnic group. At the genus level, the bacterial abundance of Faecalibacterium and Roseburia were lower in the drinkers (p < 0.05) of both communities. Gas chromatography-mass spectrometry for the detection of fecal metabolites also revealed lower butyric acid in the feces of drinkers (p < 0.05). This study showed the effects of traditionally prepared rice beer on human gut microbiota and fecal metabolites. Further research is required to understand their effect on health.

Exploring the microbiota and metabolites of traditional rice beer varieties of Assam and their functionalities.

Rice beer is traditionally prepared and consumed by various ethnic populations in the Southeast Asian countries. To understand the probable effects of rice beer on human health, present research was aimed to study biochemical parameters, microbial diversity and metabolites of major rice beer varieties of Assam, namely Apong (Poro and Nogin), Xaaj and Joubishi. Alcoholic content of rice beer varieties varied from 9.41 to 19.33% (v/v). Free radical scavenging activity against DPPH· and ABTS+ were 1.94-4.14 and 1.69-3.91 mg of ascorbic acid/ml of rice beer, respectively. In relation to antioxidant activities, phenolic content varied from 2.07 to 5.40 mg gallic acid/ml of rice beer. Next-generation sequencing of 16S rDNA showed that 18 genera of bacteria were present irrespective of rice beer varieties in which lactic acid bacteria were the dominant group (90% abundance). Functional predictions based on the bacterial profiles indicated pathways, such as metabolisms of carbohydrate, amino acid, vitamins and cofactors, and xenobiotic biodegradation, to be active in the rice beer varieties. Out of 18 core bacterial genera, 7 had correlations with the predicted functions. Gas chromatography and mass spectroscopy-based metabolite analysis revealed that the metabolite profiles of the rice beer varieties consisted of 18 saccharides, 18 organic acids, 11 sugar alcohols, 8 amino acids, 1 vitamin and nutraceutical compounds thiocoumarine, carotene, oxazolidine-2-one and acetyl tyrosine. Due to the presence of potent prebiotics, probiotics and nutraceuticals, rice beer may have health benefits which need to be studied further.

Ethnicity-Influenced Microbiota: A Future Healthcare Perspective.

Global research is focused on understanding the factors affecting human gut microbiota vis-à-vis health. Brooks et al. [PLoS Biol. (2018) 16, e2006842] has reported a group of microbial taxa that vary across ethnicity in the USA (AGP and HMP data sets). Ethnicity-specific microbial signatures will aid in developing therapeutics for targeted microbiota modulation.

An insight into gut microbiota and its functionalities.

Gut microbiota has evolved along with their hosts and is an integral part of the human body. Microbiota acquired at birth develops in parallel as the host develops and maintains its temporal stability and diversity through adulthood until death. Recent developments in genome sequencing technologies, bioinformatics and culturomics have enabled researchers to explore the microbiota and in particular their functions at more detailed level than before. The accumulated evidences suggest that though a part of the microbiota is conserved, the dynamic members vary along the gastrointestinal tract, from infants to elderly, primitive tribes to modern societies and in different health conditions. Though the gut microbiota is dynamic, it performs some basic functions in the immunological, metabolic, structural and neurological landscapes of the human body. Gut microbiota also exerts significant influence on both physical and mental health of an individual. An in-depth understanding of the functioning of gut microbiota has led to some very exciting developments in therapeutics, such as prebiotics, probiotics, drugs and faecal transplantation leading to improved health.

Role of probiotic Lactobacillus fermentum KKL1 in the preparation of a rice based fermented beverage.

A dominant lactic acid bacteria, Lactobacillus fermentum KKL1 was isolated from an Indian rice based fermented beverage and its fermentative behavior on rice was evaluated. The isolate grown well in rice and decreased the pH, with an increase of total titratable acidity on account of high yield in lactic acid and acetic acid. The production of α-amylase and glucoamylase by the strain reached plateau on 1st and 2nd day of fermentation respectively. The accumulation of malto-oligosaccharides of different degrees of polymerization was also found highest on 4th day. Besides, phytase activity along with accumulation of free minerals also unremittingly increased throughout the fermentation. The fermented materials showed free radical scavenging activity against DPPH radicals. In-vitro characteristics revealed the suitability of the isolate as probiotic organism. The above profiling revealed that probiotic L. fermentum KKL1 have the significant impact in preparation of rice beer and improves its functional characteristics.

Microbial, saccharifying and antioxidant properties of an Indian rice based fermented beverage.

Haria, a popular rice based ethnic fermented beverage, is consumed as a staple food and refreshing drink by the vast number of Indian tribal people. In this study, the composition of microbial consortia and the occurrence of some important nutraceuticals during haria preparation were investigated. The quantities of moulds and yeasts were highest at 2nd day, and then declined, but, on the contrary, the quantity of Lactic Acid Bacteria and Bifidobacterium sp. increased concurrently during the course of fermentation. Accumulation of starch hydrolytic enzymes along with different types of malto-oligosaccharides like maltotetrose (26.18µg/gm), maltotriose (28.16µg/gm), and maltose (26.94µg/gm) were also noted. Furthermore, GC-MS analysis indicated the occurrence of pyranose derivatives in the fermented products. The fermented materials showed higher free radicals scavenging activity (82.54%, 4th day) against DPPH radicals. These studies clearly demonstrated that the microbial interaction during fermentation of rice makes it more nutritious, and most likely more beneficial for health.

Modulation of small intestinal homeostasis along with its microflora during acclimatization at simulated hypobaric hypoxia.

At high altitude (HA) hypobaric hypoxic environment manifested several pathophysiological consequences of which gastrointestinal (GI) disorder are very common phenomena. To explore the most possible clue behind this disorder intestinal flora, the major player of the GI functions, were subjected following simulated hypobaric hypoxic treatment in model animal. For this, male albino rats were exposed to 55 kPa (approximately 4872.9 m) air pressure consecutively for 30 days for 8 h/day and its small intestinal microflora, their secreted digestive enzymes and stress induced marker protein were investigated of the luminal epithelia. It was observed that population density of total aerobes significantly decreased, but the quantity of total anaerobes and Escherichia coli increased significantly after 30 days of hypoxic stress. The population density of strict anaerobes like Bifidobacterium sp., Bacteroides sp. and Lactobacillus sp. and obligate anaerobes like Clostridium perfringens and Peptostreptococcus sp. were expanded along with their positive growth direction index (GDI). In relation to the huge multiplication of anaerobes the amount of gas formation as well as content of IgA and IgG increased in duration dependent manner. The activity of some luminal enzymes from microbial origin like a-amylase, gluco-amylase, proteinase, alkaline phosphatase and beta-glucuronidase were also elevated in hypoxic condition. Besides, hypoxia induced in formation of malondialdehyde along with significant attenuation of catalase, glutathione peroxidase, superoxide dismutase activity and lowered GSH/GSSG pool in the intestinal epithelia. Histological study revealed disruption of intestinal epithelial barrier with higher infiltration of lymphocytes in lamina propia and atrophic structure. It can be concluded that hypoxia at HA modified GI microbial imprint and subsequently causes epithelial barrier dysfunction which may relate to the small intestinal dysfunction at HA.

Hypobaric-hypoxia induces alteration in microbes and microbes-associated enzyme profile in rat colonic samples.

Present study deals with the straight impact of hypobaric hypoxia on the quantity and composition of some predominant fecal microflora and its functional aspects. For that, isolated fecal contents of rat were exposed to two different simulated air pressures (70 kPa and 40 kPa) for different time durations (1, 3, and 5 h) and the bacterial community composition was compared with normobaric groups (101.3 kPa). It was found that the total anaerobes, Escherichia coli, Enterbacters spp., Bifidobacterium spp., Clostridium spp. were increased whereas total aerobes were decreased at both hypobaric treatments. The increased number of amplicon was detected in the pressure-treated groups than the control that clearly mentioned the disruption of microbiota structure at different simulated hypobaric-hypoxia. The amylase, protease, tannase, ß-glucuronidase, and alkaline phosphatase activities were increased at these atmospheric pressures. Thus, the present investigation demonstrates that the hypobaric hypoxia is an important environmental factor which can strongly modulate the composition of intestinal flora as well as microflora-derived functional aspects.

Dynamics of predominant microbiota in the human gastrointestinal tract and change in luminal enzymes and immunoglobulin profile during high-altitude adaptation.

High-altitude (HA) visitors like pilgrims, trackers, scientists and military personnel face a group of nonspecific gastrointestinal (GI) symptoms during acclimatization to hypobaric hypoxia. In order to investigate the alteration of indigenous gastrointestinal microbiota in the development of such GI symptoms, an experiment was conducted for the enumeration of dominant cultivable faecal microbiota of 15 soldiers at base level (Delhi) and during their 15-day acclimatization at 3,505 m HA (Leh). At HA, faecal microbiota analysis revealed that total aerobes decreased significantly with increase of total and facultative anaerobes. The strict anaerobes like Bifidobacterium sp., Bacteroidetes sp. and Lactobacillus sp. exhibited positive growth direction index (GDI) like other predominant obligate anaerobes Clostridium perfringens and Peptostreptococcus sp. Different enzymes like amylase, proteinase and polyphenol hydrolase produced by different bacterial populations showed positive GDI, whereas phosphatase producers exhibited negative GDI. The levels of microbe-originated enzymes like amylase, proteinase, alkaline phosphatase and ß-glucuronidase were also elevated during HA acclimatization. In addition, in vitro gas production ability was enhanced with increase of faecal immunoglobulins IgA and IgG. We demonstrated that hypoxic environment at HA had the potential to alter the gut microbial composition and its activities that may cause GI dysfunctions.

Potentialities of newly isolated Bacillus subtilis and Lactobacillus sp for curd preparation and a comparative study of its physico-chemical parameters with other marketed curds.

Two Bacillus sp. were isolated from the local fermented milk and identified on the basis 16S rRNA sequence profile as Bacillus subtilis AKL1 and by biochemical process as Lactobacillus acidophilus AKL2. These isolates were used as fresh inoculums for curd preparation individually and in combinations. Different physico-chemical and therapeutic properties of the newly prepared curd were examined and compared with marketed local (sweet and sour) and branded (Mother Dairy and Thackar) curds. The total hydrolyzed peptides, free amino acids, lactic acid were significantly higher, whereas, total solid, ash content, syneresis and free reducing sugar were lower in the curd prepared by a mixture of AKL1 and AKL2 (0.5:0.5, v/v). The antioxidant activity against ABTS+, DPPH8, OH* and Fe3+ were also higher in the newly formulated curd. Polyphenols (85.5 microg/g), flavonoids (12.5 microg/g) and free aromatic amino acids contents were also higher in AKL1+AKL2. All these components prevent excess protein oxidation that was revealed by SDS-PAGE. The curd also exhibited potent antimicrobial activity against some entero-pathogens like Clostridium perfringens, Escherichia coli, Shigella dysentery, Vibrio cholerae and Staphylococcus aureus. It can be concluded that the combination of these Lactobacillus sp. will be a fruitful inoculum for the preparation of curd having better health promoting effects.

Exploitation of fermented shrimp-shells hydrolysate as functional food: assessment of antioxidant, hypocholesterolemic and prebiotic activities.

In the present study the bioactivities of chitooligosaccharides of fermented shrimp-shell hydrolysate (SSH) in respect to hypocholesterolemic, antioxidant and prebiotic activity were tested in male albino rat. Rats were treated with four different diets, viz., (i) cholesterol-rich (5%) basal diet (ChB), (ii) ChB+10% chitin, (iii) ChB+10% SSH and (iv) control group (without cholesterol). After 4 weeks of treatment, body mass index, liver weight, serum total cholesterol and LDL-cholesterol in groups (ii) and (iii) were decreased significantly than group (i). SSH supplementation significantly resists oxidative stress by reducing the thiobarbituric acid reactive substances and by increasing catalase, superoxide dismutase and free radical scavenging activity. The colonization of Lactobacillus and Bifidobacterium population in small and large intestine were more in group (iii) than other groups. Reduction of Clostridium perfringens population and non-significant changes of E. coli was also noted in SSH supplement group. Histological study revealed that the villus height and villus:crypt of the small intestine were increased significantly in SSH supplemented group (iii) without any diarrheal symptoms. The results demonstrated that the shrimp-shells hydrolysate has hypocholesterolemic effect, can resist lipid peroxidation and can influence the growth of health beneficial microbes, hence can be used as functional food for hypercholesterolemic patients.

Analysis of alteration of gut microbial population under the exposure of graded hyperbaric pressures: application of metagenomic approach.

Gastroenterological disorders are very common at hyperbaric conditions. The present study was conducted to find out the impact of gut flora on the gastrointestinal disorders created at such environmental circumstances. For this, male albino rat were exposed to graded hyperbaric pressures (915 and 1277 mmHg) and large intestinal content was examined for microbial composition using culture based and PCR-DGGE tools. After 30 day exposure, total aerobes (38.54 and 375.57 folds, 1.35 and 1.58 gdi) and E. coli (126.05 and 873.23 folds, 1.31 and 1.44 gdi) were increased whereas total anaerobes (7.01 x 10(4) and 8.84 x 10(3) folds, -1.56 and -1.39 gdi), Enterobacter spp. (-2.45 and -1.00 gdi) and Clostridium perfringens (12.88 and 54.16 folds, -1.38 and -1.75 gdi) were decreased significantly in respect to control after exposure of simulated hyperbaric pressures like at 915 and 1277 mmHg, respectively. Metagenomics study revealed an overall reduction in total microbial profile was noted than control at higher level hyperbaric pressure, i.e., 1277 mmHg air pressure for highest duration of exposure. Though, some new bands also appeared which indicated the expansion of dormant or new microbiota, Variation in the numbers of these newly dominated bacteria was correlated to dose and duration of hyperbaric treatment. The histological results clearly indicated that hyperbaric environment induced severe inflammation in the mucosal and submucosal layer of large intestine. Thus, the result suggest that hyperbaric pressure is an important exogenous factor that strongly modulated the intestinal morphology and microbial ecology, and induced several gastrointestinal ailments during hyperbarism.

Study of the cultivable microflora of the large intestine of the rat under varied environmental hyperbaric pressures.

BACKGROUND/PURPOSE(S): We conducted an in vivo experiment to investigate the effect of hyperbarometric air pressure on the quantity and composition of the cultivable microflora of the large intestine. METHODS: Using selective culture-based methods, we enumerated from the large intestine total aerobes and total anaerobes, and indicator bacteria such as Escherichia coli, other Enterobacteriaceae, Bifidobacterium spp., Lactobacillus spp. and Clostridium perfringens, and studied their quantitative variation. RESULTS: Total aerobes and facultative anaerobes (E. coli and other Enterobacteriaceae) were increased with an increase in air pressure, whereas the increase caused a drastic reduction in the numbers of total anaerobes and Clostridium perfringens. Bifidobacterium spp. and Lactobacillus spp. were affected slightly by the altered air pressures. Variation in the numbers of these groups of bacteria was correlated to dose and duration of hyperbaric treatment. CONCLUSION: We conclude from our results that air pressure is an important exogenous factor that strongly modulates bacterial colonization of the large intestine and the composition of the intestinal microflora, and that the occurrence of gastrointestinal disorders during hyperbarism is a result of alteration in the indigenous microflora.

Xylanase isozymes from the newly isolated Bacillus sp. CKBx1D and optimization of its deinking potentiality.

Recycling of civic paper waste by enzyme-based technology is nowadays a point of much concern for pollution-less green environment. In this study, the deinking effectiveness of purified xylanase from a newly isolated bacterium was evaluated for recycling of laser jet paper waste. A potent xylanases-producing bacterium from the microbial consortia of termite gut was isolated, which was further identified on the basis of 16S rRNA sequence as Bacillus sp. CKBx1D. In submerged fermentation condition, the isolate produced the highest level of xylanase (480 U/ml) at 36 h of growth. The extracellular xylanase system comprises of three distinct isozymes (est. Mw 35.28, 28.63, 18.94 kDa). The deinking of laser printed paper waste was performed using the purified enzyme mixture. Whole operational parameters were optimized using the Response Surface Methodology; it was found that at pH 6.8 with 47.2 h of continuous shaking at constant temperature of 35 °C, enzymes showed best deinking activity. After enzyme treatment, the physical properties of the pulp like brightness and ERIC (effective residual ink content) values were enhanced, whereas the pulp opacity was more reduced than the control treatment. Hence, the bacterial isolate and its xylanolytic enzyme system could efficiently be used in recycling paper waste as deinking agent.