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.