Author: Lisa Spriet, Registered Dietitian, MSc, RD
How Does Gut Health Impact Fatty Liver Disease?
Gut health and fatty liver disease are directly connected through what researchers call the gut–liver axis. If you’ve been diagnosed with MASLD (Metabolic dysfunction-Associated Steatotic Liver Disease, formerly known as NAFLD), or if your doctor has flagged elevated liver enzymes, understanding what’s happening in your gut is an important part of your care.
What Is the Gut–Liver Axis?
The gut–liver axis refers to the close anatomical and functional relationship between the gut and the liver. Blood from the intestines flows directly to the liver via the portal vein — meaning everything that passes through the gut lining has a direct route to the liver.
When the gut microbiome is balanced, this relationship works well. But when dysbiosis (microbial imbalance) increases intestinal permeability — allowing bacterial endotoxins like lipopolysaccharide (LPS) to leak into the portal circulation — the liver is the first organ to take the hit. That chronic low-level endotoxin exposure drives hepatic inflammation, fat accumulation, and disease progression in MASLD.
Can Gut Health Cause Fatty Liver Disease?
Gut dysbiosis contributes to fatty liver disease through several mechanisms. A disrupted microbiome increases intestinal permeability, raises circulating inflammatory signals, alters bile acid metabolism, and impairs the regulation of fat storage in the liver. Research consistently shows that people with MASLD have distinct gut microbiome profiles compared to healthy controls — with lower populations of beneficial SCFA-producing bacteria and higher levels of pro-inflammatory species.
This doesn’t mean gut dysbiosis is the only cause of MASLD — metabolic factors like insulin resistance, excess calorie intake, and sedentary behaviour all play a role. But the gut–liver connection is now well-established enough that supporting gut health is considered a front-line strategy in MASLD management.
Do Probiotics Help With Fatty Liver Disease?
Probiotics for fatty liver disease show meaningful clinical benefit in current research. A 2025 umbrella meta-analysis of 12 randomized controlled trials found that probiotic and synbiotic supplementation significantly improved liver function markers (ALT, AST), lipid profiles, and inflammatory markers in people with MASLD. Combinations of Lactobacillus, Bifidobacterium, and Streptococcus strains appear most effective, with interventions of at least 12 weeks showing the clearest results.
Because there is currently no approved pharmacotherapy for most stages of MASLD, nutritional and microbiome-targeted approaches are not optional add-ons — they are central to evidence-based management.
What Diet Is Best for Gut Health and Fatty Liver?
Diet for fatty liver and gut health works best when it addresses both the liver and the microbiome simultaneously. The most well-supported approach combines:
- High dietary fibre from vegetables, legumes, whole grains, and fruit — to feed SCFA-producing bacteria and reduce hepatic inflammation
- Mediterranean-style eating — the most evidence-supported dietary pattern for both MASLD and microbiome health; associated with reduced liver fat and improved metabolic markers
- Limiting ultra-processed foods, added sugars, and refined carbohydrates — key drivers of both dysbiosis and hepatic fat accumulation
- Adequate protein from lean sources — to support liver cell regeneration
- Reducing or eliminating alcohol — even moderate amounts contribute to gut permeability and liver stress
Fermented foods (yogurt, kefir, sauerkraut, kimchi) and prebiotic-rich vegetables (garlic, onions, legumes, oats) help restore microbial balance as part of a broader dietary approach.
How Can a Dietitian Help With Fatty Liver Disease?
A Registered Dietitian for fatty liver provides the individualized guidance that general nutrition advice can’t. That includes assessing the full dietary and metabolic picture, setting calorie and macronutrient targets appropriate for your liver health goals, introducing gut-supportive foods and supplements at a pace your body can tolerate, and coordinating with your medical team on monitoring markers like ALT, AST, and lipids.
NutriProCan dietitians have experience working with clients managing MASLD alongside related conditions including type 2 diabetes, elevated cholesterol, and obesity — covered by most extended health benefit plans.
Book a free 15-minute consultation to learn more about our Liver Health services → https://nutriprocan.ca/free-consult/
References
Kurban, G. et al. (2025). Microbial therapy on hepatic steatosis in MASLD: umbrella meta-analysis. Frontiers in Nutrition.
Al-Habsi, N. et al. (2024). Health Benefits of Prebiotics, Probiotics, Synbiotics, and Postbiotics. Nutrients, 16(22), 3955.
Perrone, P. & D’Angelo, S. (2025). Gut Microbiota Modulation Through Mediterranean Diet Foods. Nutrients, 17(6), 948.
Di Vincenzo, F. et al. (2023). Gut microbiota, intestinal permeability, and systemic inflammation. Internal and Emergency Medicine.
Author: Lisa Spriet, MSc, RD
Lisa Spriet is a Registered Dietitian and Co-Owner of NutriProCan, a national company of dietitians dedicated to improving health through nutrition. With over 20 years of experience in fitness, health, and wellness, she combines clinical expertise with entrepreneurial leadership. Lisa holds a Master of Science in Foods & Nutrition, has taught nutrition at Brescia University College (now Western University), and is a sought-after speaker at corporate wellness and health industry events. Lisa is known for creating innovative nutrition programs and leading a team of dietitians across Canada.
About NutriProCan: We are a Canadian virtual dietitian clinic offering personalized nutrition support in Ontario, Alberta and British Columbia. Our registered dietitians, licensed in Canada, provide evidence-based guidance for weight management, chronic conditions, women’s health, fitness and sports performance, couples’ nutrition coaching and more!