In a study published last week in Nutrients, researchers investigated the potential benefits of probiotics in metabolic diseases, including obesity, type 2 diabetes, hypertension, and dyslipidemia. Past research has demonstrated the association of the gut microbiome with metabolic markers and type II diabetes.
In this new study, researchers designed a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014. Probiotic consumption was considered when an individual reported eating yogurt or a probiotic supplement during the 24-hour recall or the Dietary Supplement Use 30-Day questionnaire. This study included 38,802 individuals and 13.1% reported consuming probiotics. As a result, the incidence of obesity and hypertension was lower in the probiotic group. Body mass index (BMI), systolic and diastolic pressure, and triglycerides were all lower and HDL was higher in the probiotic group.
Previous research has shown that it is not the body fat alone but the increased low grade inflammation and metabolic dysfunction causing the disease. This promotes insulin resistance in the liver and the release of inflammatory mediators from the adipose tissue. In addition, increased intestinal permeability allows translocation of proinflammatory lipopolysaccharides.
There is evidence that age-related changes in the gut microbiome may be related to elevated inflammatory makers. As one ages, the gut has an increase in interleukin 6 (IL-6) which causes the immune system to release IL-6 and trigger inflammation. Increased levels of IL-6 directly lead to increased intestinal permeability with no physical differences seen in its structure. Probiotics have the potential to rebalance gut microbiota and modulate the gut immune response inhibiting the NF-κB pathway.
Other research has indicated that obesity has a microbial component that alters the caloric extraction from ingested food. For example, if one has more Bacteroidetes bacteria, the individual tends to be leaner. High Firmicutes:Bacteroidetes ratios have been known to increase the caloric extraction from food and these individuals tend to be more obese. This also ties together the importance of dietary fiber, prebiotics, and weight loss.
Several years ago I attended a probiotic workshop at Yale where Max Nueuwdrop, MD, PHD, an internist and endocrinologist from Amsterdam, presented on this topic, discussing in detail the microbiota and metabolism. He described how butyrate, a short-chain fatty acid (SCFA), improved insulin resistance and brown fat activation. In general, low SCFAs are associated with low diversity and an abundance of the commensal bacteria. When patients introduce probiotics and increase their dietary fiber intake by consuming fruits and vegetables, the beneficial bacteria, butyrate, and SCFAs will increase.
Probiotics help encourage microbial diversity, especially if the probiotic supplement is comprised of mixed species. In ecological terms, it is more stable to have diverse populations in any ecosystem. The same is true for the gastrointestinal microbiome. This large scale study demonstrates the potential benefits of probiotic supplementation in patients with obesity and hypertension.
By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS