Your intestinal bacteria are part of your immune system and researchers have discovered that microbes of all kinds play instrumental roles in countless areas of your health. Beneficial bacteria also control the growth of disease-causing bacteria by competing for nutrition and attachment sites in your colon.
This is of immense importance, as pathogenic bacteria and other less beneficial microbes can wreak havoc with your health if they gain the upper hand. It can also affect your weight. Moreover, your gut microbiome — which contains 100 times as many genes as your body’s total genome — is involved in important chemical reactions that your gut enzymes cannot perform, including fermentation and sulfate reduction.
Importantly, your gut microbiome helps generate new compounds (bacterial metabolites) that can have either a beneficial or detrimental impact on your health. Among the most recent research published are studies showing beneficial gut bacteria, also known as probiotics, benefit your liver function and help lower blood pressure.
Probiotics Influence Liver Function
While a lot of research has focused on the influence gut bacteria have on your gastrointestinal health, recent research presented at the 2018 Experimental Biology meeting in San Diego reveals probiotics also impact your liver function. This study focused primarily on a probiotic called lactobacillus rhamnosus GG (LGG), which is found in many commercial probiotic supplements.
Mice were first given food with added LGG for two weeks, and were then given a toxic dose of acetaminophen, known to cause serious liver damage by increasing oxidative stress. Interestingly, the animals pretreated with LGG had far less liver damage than untreated mice when given an acetaminophen overdose.
According to lead author Bejan Saeedi, doctoral candidate at Emory University,1 “Administration of the probiotic LGG to mice improves the antioxidant response of the liver, protecting it from oxidative damage produced by drugs such as acetaminophen.” Earlier animal studies have also shown LGG helps protect against alcoholic liver disease and nonalcoholic fatty liver disease, the latter of which is primarily driven by diets high in sugar and processed foods.
Earlier research by the same team reveals the mechanism behind this finding. It appears LGG protects the liver against oxidative damage by activating Nrf2, a biological hormetic that upregulates superoxide dismutase, catalase and other intercellular antioxidants. Nrf2 not only lowers inflammation, but also improves mitochondrial function and stimulates mitochondrial biogenesis. Aside from consuming LGG-containing probiotics, Nrf2 can also be activated by:
Consuming Nrf2-boosting food compounds such as sulforaphane from cruciferous vegetables, foods high in phenolic antioxidants, the long-chained omega-3 fats DHA and EPA, carotenoids (especially lycopene), sulfur compounds from allium vegetables, isothiocyanates from the cabbage group and terpenoid-rich foods
Performing high-intensity exercises that activate the nitric oxide (NO) signaling pathway, such as the NO dump exercise
Multiday water fasting and intermittent fasting
Molecular hydrogen
Probiotics Help Normalize Blood Pressure
Other recent findings suggest regularly consuming probiotics can help relieve hypertension (high blood pressure). One previous analysis2 of nine studies that scrutinized associations between probiotics and blood pressure found that people who consume probiotics on a regular basis (in the form of yogurt, kefir or supplements, for example) tended to have lower blood pressure than those who did not consume probiotics.
On average, their systolic blood pressure (the top number in a reading) was 3.6 millimeters of mercury (mm Hg) lower and their diastolic blood pressure (the bottom number) was 2.4 mm Hg lower. The most significant benefit appeared to be among those whose blood pressure was higher than 130/85, and probiotics that contained a variety of bacteria lowered blood pressure to a greater degree than those containing just one type of bacteria.
Another animal study3 published last year found the probiotic lactobacillus marinus effectively prevents salt-sensitive hypertension by modulating TH17 cells. (Other research has found high salt intake inhibits lactobacillus marinus, thereby contributing to hypertension.) According to the authors:
“In line with these findings, a moderate high-salt challenge in a pilot study in humans reduced intestinal survival of lactobacillus spp., increased TH17 cells and increased blood pressure. Our results connect high salt intake to the gut–immune axis and highlight the gut microbiome as a potential therapeutic target to counteract salt-sensitive conditions.”