Browse the evidence

Interventions targeting the gut microbiota, specifically probiotics (Lactobacillus and Bifidobacterium strains), prebiotics, and short-chain fatty acids (SCFAs), can enhance muscle mass and physical performance in aging populations.

Focus on resistance training and protein intake as primary strategies for muscle health. While gut health is important, current evidence does not support specific probiotic or prebiotic supplements as a reliable standalone treatment for sarcopenia in humans. More research is needed before these can be recommended as standard therapy.

BCAA supplementation can enhance the anabolic effect of intact protein meals (e.g., whey) by potentially overcoming rate-limiting steps or activating initiation factors, though this is distinct from the effect of BCAAs alone.

If you are consuming protein, adding BCAAs might boost the muscle-building response, potentially allowing you to get more benefit from a smaller amount of protein. However, this benefit is only seen when BCAAs are mixed with complete protein, not when taken alone.

Adherence to the Mediterranean Diet (MD) during lockdown was associated with lower BMI and reduced perception of weight gain, suggesting MD may mitigate pandemic-related metabolic stress.

Focus on the core components of the Mediterranean Diet (vegetables, fruits, legumes, nuts, olive oil, fish) even during stressful periods. This pattern is associated with lower body weight and reduced perception of weight gain, potentially offering metabolic protection against pandemic-related stress.

Increased physical activity, specifically bodyweight training, during lockdown was associated with a reduced perception of weight gain.

Incorporate bodyweight training into your routine, even during lockdown. Increasing the frequency of such training (up to 5+ days/week for some) was associated with less perceived weight gain, helping to counteract the metabolic effects of reduced mobility.

Gains in cardiorespiratory fitness (peak VO2) from aerobic exercise are correlated with improved memory performance and reduced hippocampal atrophy in early Alzheimer's disease.

To potentially support memory and brain health in early Alzheimer's, patients should aim to improve their cardiorespiratory fitness through aerobic exercise. This involves activities that raise the heart rate to a moderate intensity (60-75% of max) for 150 minutes per week. The goal is to improve fitness levels, which the study links to better memory and brain volume preservation.

Modern diets with an Omega-6 to Omega-3 ratio of 20-50:1, compared to the evolutionary ideal of 1-2:1, drive chronic inflammation and chronic disease by shifting lipid mediator production toward pro-inflammatory pathways.

Reduce your intake of seed and vegetable oils (corn, soybean, sunflower, safflower) which are high in Omega-6. Increase intake of Omega-3 sources like fatty fish, algae, or flax/chia seeds. Aim for a dietary ratio closer to 4-5:1 rather than the typical 20:1 found in modern diets to lower systemic inflammation.

Prior resistance exercise-induced hypertrophy creates an epigenetic memory in human skeletal muscle, evidenced by sustained DNA hypomethylation of specific genes (e.g., AXIN1, GRIK2, UBR5) during detraining, which facilitates a significantly greater hypertrophic response upon subsequent reloading compared to the initial training phase.

If you have trained before, stopped, and are starting again, your muscles may respond faster than when you first started. This is due to epigenetic changes (DNA methylation) that persist even after muscle mass returns to baseline. To leverage this, ensure your initial training phase was substantial enough to induce hypertrophy, as this creates the 'memory' that accelerates reloading gains.

Administration of specific probiotic strains (e.g., Lactobacillus, Bifidobacterium, Saccharomyces) improves gastrointestinal health outcomes, including reducing the duration of acute diarrhea, preventing antibiotic-associated diarrhea, and alleviating symptoms of irritable bowel syndrome (IBS).

If you are looking to use probiotics for digestive issues like diarrhea or IBS, do not just buy any probiotic. Look for specific strains like Lactobacillus rhamnosus GG or Saccharomyces boulardii, which have evidence for diarrhea. Take them 1-10 billion CFUs, 1-2 times daily. If you are taking antibiotics, wait two hours after the antibiotic before taking the probiotic. Results vary by individual, so track your symptoms.

Resistance training induces functional brain changes, particularly in the frontal lobe, which are associated with improvements in executive functions.

To support brain health and executive function, incorporate resistance training into your routine. This type of exercise has been shown to cause functional changes in the frontal lobe and reduce white matter atrophy, which are linked to better cognitive performance, especially in older adults.

Gains in dynamic muscular strength mediate improvements in global cognitive performance and executive functions.

Improving your muscular strength through resistance training can directly boost your cognitive performance and executive functions, suggesting that physical strength is a key driver of brain health.

Exercise interventions for hip or knee osteoarthritis improve self-efficacy and slightly reduce depression, but have little to no effect on anxiety.

Exercise can help boost your confidence in managing your condition and may slightly reduce depressive symptoms. However, do not expect exercise to significantly alleviate anxiety. Focus on the physical and confidence-building benefits.

Dietary fiber intake modulates gastrointestinal transit time, which serves as a key mechanism for improving glucose homeostasis and reducing the risk of metabolic diseases like obesity and type 2 diabetes.

Increase your intake of dietary fibers from various plant sources (whole grains, vegetables, legumes) to support healthy gastrointestinal transit. This can help regulate blood sugar levels and may reduce the risk of metabolic diseases. Start gradually to minimize digestive discomfort.

Viscous soluble fibers (e.g., beta-glucans, pectin, psyllium) delay gastric emptying, which contributes to reduced postprandial glucose concentrations and improved insulin sensitivity.

Incorporate viscous soluble fibers like beta-glucans (oats), pectin (apples), or psyllium into your meals. These can help slow down digestion, leading to more stable blood sugar levels after eating. Ensure adequate water intake when consuming these fibers.

Women with PCOS should be assessed for cardiovascular disease risk factors, including lipid profiles and blood pressure, regardless of age or BMI, due to increased risk of cardiovascular disease and mortality.

If you have PCOS, get your cholesterol and blood pressure checked at diagnosis and annually thereafter, even if you are young and have a healthy weight. This is standard care for PCOS, not optional.

High adherence to the Mediterranean diet is associated with lower Escherichia coli counts, a higher Bifidobacteria:E. coli ratio, increased Candida albicans levels, and greater acetate molar ratios in the gut microbiota.

Adhering closely to a Mediterranean diet pattern (high in plants, olive oil, fish; low in red meat/sweets) shifts your gut microbiota to favor beneficial ratios (Bifidobacteria/E. coli) and increase beneficial short-chain fatty acids like acetate. Note that this shift may initially increase gastrointestinal symptoms like bloating or pain, which the study observed as more pronounced in high adherers.

Consumption of snacks and junk food is negatively associated with beneficial gut bacteria (Lactobacilli, butyrate-producers) and positively associated with E. coli and coliforms.

High consumption of snacks and junk food is linked to a gut microbiota profile with fewer beneficial bacteria (like Lactobacilli and butyrate-producers) and higher levels of E. coli and coliforms. Reducing these foods may support a healthier microbial balance.

Dietary polyphenols (curcumin, quercetin, catechins) ameliorate metabolic disorders by being metabolized by gut microbiota into bioactive phenolic metabolites, which in turn modulate gut microbiota composition to favor beneficial bacteria and reduce pathogenic ones.

To get metabolic benefits from polyphenols like curcumin, quercetin, and catechins, focus on consistent dietary intake rather than expecting immediate high absorption. Your gut bacteria will process these compounds into active metabolites that help regulate inflammation and metabolic health. Diversity in your diet supports the microbial diversity needed for this conversion.

Curcumin administration improves metabolic health in obese/diabetic models by modulating gut microbiota to reduce inflammation and improve intestinal barrier function.

If you consider curcumin, understand that its benefit may come more from its interaction with your gut bacteria than direct absorption. It may help with insulin sensitivity and gut barrier integrity, especially if you have metabolic issues. Formulations that enhance bioavailability (like with piperine or lipids) may be more effective.

Quercetin supplementation reduces inflammation and improves metabolic parameters (glucose, lipids) by modulating gut microbiota composition, specifically by increasing beneficial bacteria and reducing pathogenic ones.

Quercetin, found in onions, apples, and tea, may help manage blood sugar and lipids by supporting healthy gut bacteria. Regular dietary intake is a practical way to leverage these effects.

Administration of probiotics, prebiotics, or synbiotics can improve insulin sensitivity and glucose metabolism in humans, primarily through mechanisms involving short-chain fatty acid (SCFA) production, modulation of gut microbiota composition, and reduction of systemic inflammation.

If you have insulin resistance or type 2 diabetes, consuming specific probiotic strains (like Lactobacillus and Bifidobacterium combinations) or prebiotics (like inulin or FOS) may help improve your blood sugar control. However, results are not guaranteed and depend heavily on the specific strain and dose used. It is not a substitute for standard medical care but may be a useful adjunct.

Probiotic supplementation can reduce systemic inflammation and oxidative stress, which are contributors to insulin resistance, by lowering pro-inflammatory cytokines and increasing antioxidant enzyme activity.

Some probiotic supplements may help lower chronic inflammation and oxidative stress in people with diabetes, which can indirectly support better insulin sensitivity.

Dietary omega-3 polyunsaturated fatty acids (EPA, DHA, ALA) modulate gut microbiota composition by increasing beneficial bacteria (Bifidobacteria, Lactobacilli, Akkermansia) and decreasing pathogenic or pro-inflammatory bacteria (Enterobacteria, Firmicutes-to-Bacteroidetes ratio), thereby improving intestinal barrier function and reducing systemic inflammation.

To support gut health and reduce inflammation, ensure adequate intake of omega-3 fatty acids (EPA and DHA) through diet (fatty fish) or supplementation. This helps increase beneficial gut bacteria like Bifidobacteria and reduces harmful bacteria, supporting intestinal barrier integrity. This is particularly relevant if you have conditions like obesity or IBD.

Omega-3 PUFAs reduce intestinal inflammation and immune response by inhibiting pro-inflammatory signaling pathways (NF-κB, MAPK) and promoting anti-inflammatory mediators (IL-10, SCFAs like butyrate).

If you suffer from inflammation or gut issues, omega-3s (EPA/DHA) can help by directly reducing inflammatory signaling in the gut. This is achieved by blocking pro-inflammatory pathways and boosting anti-inflammatory factors. This benefit is most pronounced when using direct sources of EPA/DHA rather than just plant-based ALA.

Omega-3 PUFAs can alleviate symptoms of Non-Alcoholic Fatty Liver Disease (NAFLD) and obesity by modulating gut microbiota and reducing hepatic lipid content.

For those with NAFLD or obesity, omega-3 supplementation (EPA/DHA) can help reduce liver fat and improve metabolic markers. This is achieved by modulating gut bacteria and reducing inflammation. It is a supportive strategy alongside lifestyle changes.