Consumption of Fermented Foods Is Associated with Systematic Differences in the Gut Microbiome and Metabolome

This study examines the gut microbiome of fermented food consumers versus non-consumers involved in the American Gut Project. 16S rRNA amplicon sequencing revealed subtle, but statistically significant, compositional differences in the gut microbiome profiles of fermented food consumers. The consumption of fermented foods was associated with a gut microbiota enriched in microbes known to be derived from fermented foods, including fermented milk products (Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus kefiranofaciens, Lactobacillus parabuchneri, and Lactobacillus helveticus) and fermented meat (Lactobacillus sakei). Interestingly, the metabolome of fermented food consumers was enriched with conjugated linoleic acid (CLA), known for its beneficial health effects. The increase in CLA was not associated with intake of foods rich in CLA such as dairy, eggs, or meat, but is believed to be associated with microbial production. Further study is required, but the researchers hypothesize the putatively beneficial health effects of fermented foods may be related to CLA production as a result of the microbes found in fermented foods.

A high-salt diet compromises antibacterial neutrophil responses through hormonal perturbation

Researchers from the University of Bonn have discovered how excess salt intake impairs the immune system in mice and humans. This elegant study found that mice exposed to a high salt diet had an impaired neutrophil response so were less able to rid themselves of ingested bacteria such as Listeria monocytogenes and E. coli. The results were supported by a follow-up study in healthy volunteers consuming 6 grams of sodium in addition to their regular diet (the equivalent of two fast food meals). Researchers collected the subjects' serum and found that the neutrophils did not respond as strongly when exposed to the high salt diet, concluding that a high salt diet could potentially increase vulnerability to bacterial infections.

Long-term dietary intervention reveals resilience of the gut microbiota despite changes in diet and weight

Researchers from Stanford found that neither baseline microbiome composition nor baseline diversity predicts the degree of weight loss on either a healthy low-carbohydrate (low-carb) or low-fat diet for weight loss. The Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) clinical trial was a year-long dietary intervention study that included 609 generally healthy, nondiabetic participants. Participants lost weight but despite initial taxonomic changes to the microbiota during the first 3 months of the intervention, the microbiota returned to baseline for the remaining 9 months of the study.

Effects of Probiotics on Patients with Hypertension: a Systematic Review and Meta-Analysis

Do probiotics have any effects on hypertension? This publication concluded that probiotic consumption results in a 4.81 mmHg (95% CI 1.53, 8.09) reduction in systolic blood pressure in individuals with pre-existing hypertension. This systematic review examined 11 studies involving 628 patients. The efficacy of probiotic supplementation was associated with treatment duration, dosage, and the age of subject, but not single versus multiple strain usage. People receiving a treatment for longer than 4 weeks and a dosage of more than 2 × 10(10) CFUs showed a more pronounced reduction in blood pressure. Patients older than 60 years benefited less from probiotic supplementation.

Metabolites Linking the Gut Microbiome With Risk for Type 2 Diabetes

Microbial metabolites play a complex role in the regulation of host metabolism and maintenance of the gut microbiome, and as a result they have been linked to insulin resistance and type 2 diabetes. This review discusses the key mechanisms of how several important metabolites (e.g., short-chain fatty acids, bile acids, sulfur-containing amino acids, branched-chain amino acids, lipopolysaccharide, etc.) influence the gut microbiome and how they are linked specifically to type 2 diabetes.