Buttermilk contains several compounds that appear to support liver health, though the evidence is mostly from animal experiments and observational population studies rather than clinical trials in humans. Its unique mix of milk fat globule membrane, live bacterial cultures, and phospholipids gives it properties that go beyond those of ordinary milk. A large prospective study found that people who consumed the most fermented dairy products had roughly a 21% lower risk of developing fatty liver disease and about a 29% lower risk of cirrhosis compared to those who consumed the least. That is encouraging, but the full picture involves some important caveats about the type of buttermilk, who benefits, and what the research can actually prove.
What Population Studies Show About Dairy and Liver Disease
The strongest human evidence comes from large cohort studies that tracked dairy intake alongside liver outcomes over years. A prospective study using data from the UK Biobank examined different types of dairy products and found that higher intake of fermented dairy was linked to lower risks of both nonalcoholic fatty liver disease and cirrhosis. Comparing the highest-intake group to the lowest, fermented dairy was associated with a 21% lower risk of fatty liver disease and a 29% lower risk of cirrhosis. Low-fat dairy products showed a similar pattern, while high-fat dairy showed no significant association with either condition.1PubMed. Intake of the different types of dairy products, genetic predisposition, and the risks of nonalcoholic fatty liver disease and cirrhosis: a prospective cohort study
A separate study following Korean adults found a similar trend, but with an interesting twist: the protective association between dairy and liver disease was significant in men but not in women. Men with the highest total dairy consumption had about a 21% lower risk of metabolic-associated steatotic liver disease compared to men with the lowest intake. Milk and yogurt drove most of that benefit, while cheese consumption showed no significant link in either sex.2PubMed. Association between dairy consumption and metabolic dysfunction-associated steatotic liver disease among Korean adults: Evidence from the prospective health examinees cohort
Observational studies like these cannot prove that buttermilk or any dairy product directly prevents liver disease. People who drink more fermented dairy may also eat differently, exercise more, or have other habits that protect their livers. Still, the consistency of the finding across populations and the specificity of the association with fermented and low-fat dairy products (the categories buttermilk falls into) makes the connection worth taking seriously.
Milk Fat Globule Membrane and Liver Fat
One reason buttermilk stands out from other dairy drinks is its unusually high concentration of milk fat globule membrane, or MFGM. When cream is churned into butter, the thin membranes that surround each fat droplet in whole milk get stripped away and concentrated in the liquid left behind. That liquid is buttermilk. MFGM is rich in phospholipids and sphingomyelin, compounds that influence how the body absorbs and processes dietary fat.
In a mouse study, supplementing the diet with MFGM during early life protected against fatty liver later on, even when the animals’ mothers had eaten a high-fat diet. Mice that received MFGM had significantly less fat accumulation in their livers as adults compared to mice on the same high-fat maternal diet without MFGM. Liver triglyceride levels in the MFGM-supplemented group were close to those of mice raised on a normal diet, whereas the unsupplemented high-fat group had roughly 38% more liver fat than controls.3The Journal of Nutrition. Milk Fat Globule Membrane Supplementation During Suckling Ameliorates Maternal High Fat Diet–Induced Hepatic Steatosis in Adult Male Offspring of Mice
The phospholipids in MFGM also appear to change how dietary fat is handled in the gut itself. Research on milk polar lipids found that they can inhibit the assembly of large fat-carrying particles during digestion and increase the breakdown of triglycerides in the intestinal lumen. The net effect is less of a surge of fat in the bloodstream after a meal, which over time could reduce the load of fat that reaches the liver for processing.4Nutrition Reviews. Cardiometabolic health benefits of dairy-milk polar lipids
How the Gut-Liver Connection Factors In
Your liver receives blood directly from your intestines through the portal vein. Everything your gut absorbs, including bacterial toxins if the gut barrier is compromised, goes to the liver first. This gut-liver axis is a major pathway through which diet influences liver health, and fermented foods like buttermilk can affect it at several points.
A review of the evidence on fermented foods and metabolic-associated steatotic liver disease found that fermented products supply probiotics, short-chain fatty acids, and other bioactive compounds that improve microbial diversity, strengthen the intestinal barrier, and reduce the leakage of bacterial toxins into the bloodstream. That reduction in what researchers call endotoxemia can dampen the chronic low-grade inflammation that drives fatty liver disease forward.5PubMed Central. Fermented Foods and the Gut–Liver Axis: Modulation of MASLD Through Gut Microbiota
The probiotic angle has been explored specifically in the context of alcohol-related liver injury, too. In a rat model of alcoholic liver disease, supplementation with Lactobacillus GG (a well-studied probiotic strain) reduced gut leakiness, lowered markers of oxidative stress in both the intestine and the liver, and significantly improved liver inflammation. The key mechanism was preserving gut barrier function so that fewer toxic bacterial products reached the liver in the first place.6PubMed Central. Lactobacillus GG treatment ameliorates alcohol-induced intestinal oxidative stress, gut leakiness, and liver injury in a rat model of alcoholic steatohepatitis
Cultured buttermilk typically contains live Lactobacillus and other lactic acid bacteria. Whether the specific strains and doses present in a glass of buttermilk are enough to replicate these experimental results in humans remains an open question, but the direction of the evidence is consistent.
Effects on Cholesterol and Triglycerides
Fatty liver disease is tightly linked to blood lipid levels. Excess circulating triglycerides and cholesterol get deposited in liver cells, so anything that improves blood lipids can indirectly benefit the liver. Buttermilk has been tested for exactly this in a controlled human trial.
When healthy adults drank buttermilk daily for several weeks, their total serum cholesterol dropped by about 3%, and their triglycerides fell by roughly 11%. LDL cholesterol also trended downward. The cholesterol-lowering effect appeared to be linked to changes in how the body absorbs plant sterols, suggesting that buttermilk’s phospholipids interfere with cholesterol uptake in the gut rather than altering cholesterol production in the liver.7Nutrition, Metabolism and Cardiovascular Diseases. Impact of buttermilk consumption on plasma lipids and surrogate markers of cholesterol homeostasis in men and women
An 11% drop in triglycerides is meaningful. Elevated triglycerides are one of the hallmarks of metabolic syndrome and a direct contributor to fat buildup in the liver. For someone whose blood lipids are borderline high, adding buttermilk to the diet could help keep those numbers in a safer range. But for someone with severely elevated lipids, buttermilk alone would be unlikely to replace medication.
Fermented Milk and Liver Inflammation in Animal Models
Several animal studies have directly tested fermented milk against fatty liver disease, using formulations similar to cultured buttermilk. In one experiment, rats fed a high-fat diet to induce nonalcoholic fatty liver disease were then given fermented milk containing Lactobacillus rhamnosus for eight weeks. The treatment significantly reduced liver enzymes (markers of liver cell damage), lowered inflammatory markers in the blood, and decreased the number of fat-filled cells visible in liver tissue. The researchers attributed the improvement to changes in lipid metabolism and amino acid pathways.8PubMed. Beneficial effects of Lactobacillus rhamnosus hsryfm 1301 fermented milk on rats with nonalcoholic fatty liver disease
A separate study on hyperlipidemic rats found that probiotic-fermented milk improved triglyceride levels by shifting gene activity in the liver, turning down genes involved in converting carbohydrates to fat and turning up genes that promote fat burning.9PubMed Central. Effects of Single Probiotic- and Combined Probiotic-Fermented Milk on Lipid Metabolism in Hyperlipidemic Rats
These are animal studies, so they tell us about biological plausibility rather than proven human benefit. Rats metabolize dairy differently than people do, and the doses of probiotics in these experiments were typically much higher per body weight than what you would get from drinking buttermilk. Still, the mechanisms they point to, reduced liver inflammation, improved fat metabolism, and better gut barrier function, are consistent with what the human epidemiological data suggests.
The Microbiome and Metabolic Ripple Effects
Fermented milk products change what your gut bacteria produce, and those bacterial metabolites travel to the liver and influence how it works. A narrative review of fermented milk and gut-derived metabolites found that regular consumption increases the abundance of beneficial bacteria like Lactobacillus and Bifidobacterium, boosts the production of short-chain fatty acids, and improves bile acid profiles. These effects collectively improve insulin sensitivity, reduce systemic inflammation, and support healthier lipid levels, all of which take pressure off the liver.10PubMed. The Impact of Fermented Milk Products on Gut Microbiota-Derived Metabolites in Obesity: A Narrative Review
Insulin resistance deserves special mention because it is one of the central drivers of fatty liver disease. When cells stop responding well to insulin, the liver compensates by ramping up fat production. Anything that improves insulin sensitivity, including the metabolic effects of fermented dairy, can help break that cycle. The review noted that these benefits are mediated through bile acid receptors and inflammatory signaling pathways, meaning the effect is not just about dumping probiotics into the gut but about changing the chemical messages the gut sends to the liver.
The individual variability here is real, though. How much benefit you get from fermented dairy depends partly on the composition of your existing microbiome. Someone whose gut already has a thriving population of beneficial bacteria may see less dramatic changes than someone whose microbiome is disrupted by a poor diet or antibiotics.
Traditional Buttermilk vs. Store-Bought Cultured Buttermilk
Not all buttermilk is created equal when it comes to bioactive compounds. Traditional buttermilk is the liquid left after churning butter from cream. Cultured buttermilk, the kind sold in most grocery stores, is made by fermenting low-fat or skim milk with lactic acid bacteria. Both contain live cultures if unpasteurized, but they differ significantly in their MFGM content and in how processing affects their bioactivity.
A study comparing buttermilk from raw cream versus pasteurized cream found a stark difference in cholesterol-lowering potential. Raw-cream buttermilk reduced cholesterol solubility in a lab model by about 57%, while buttermilk made from pasteurized cream managed only about a 17% reduction. Pasteurization appears to damage some of the phospholipid structures responsible for the effect. Interestingly, treating the pasteurized buttermilk with enzymes partially restored its activity, suggesting that the bioactive components are still present but in a less functional form after heat treatment.11Dairy Science and Technology. Effect of cream pasteurization, microfiltration and enzymatic proteolysis on in vitro cholesterol-lowering activity of buttermilk solids
For practical purposes, this means that commercially available cultured buttermilk probably delivers weaker liver-relevant effects than traditional buttermilk from a farm or artisan dairy. If you are specifically interested in the MFGM-related benefits, seeking out buttermilk made from minimally processed cream could make a difference. That said, cultured buttermilk still provides probiotics, protein, and some phospholipids, so it is not without value.
Whey Proteins and Oxidative Stress
Buttermilk contains whey proteins, and these have their own line of evidence related to liver protection. Oxidative stress, the accumulation of reactive molecules that damage cells, is a key driver of liver inflammation and fibrosis. Dietary intervention studies in both animals and humans have found that consuming whey products can shift markers of oxidative stress in a favorable direction. Part of this effect comes from whey-derived peptides that act as antioxidants, and part comes from whey’s ability to boost the body’s own production of glutathione, a major internal antioxidant that the liver depends on heavily.12Free Radical Research. Whey proteins: targets of oxidation, or mediators of redox protection
The liver is the body’s primary detoxification organ, and it generates large amounts of reactive oxygen species as a byproduct of its work. Anything that supports antioxidant defenses in the liver is at least theoretically beneficial, and whey proteins are one of the better-studied dietary sources for this purpose.
Who Might Not Benefit
The sex-specific finding from the Korean cohort study is worth pausing on. That study found a significant protective association between dairy intake and liver disease in men but not in women.2PubMed. Association between dairy consumption and metabolic dysfunction-associated steatotic liver disease among Korean adults: Evidence from the prospective health examinees cohort The reasons are not fully understood, but hormonal differences in how men and women metabolize fat and respond to insulin could play a role. It does not mean buttermilk is harmful for women; it means the liver-specific benefits may be less pronounced or harder to detect in female populations.
People with lactose intolerance often tolerate buttermilk better than regular milk because fermentation breaks down a portion of the lactose. However, it is not lactose-free, so someone with severe intolerance may still react to it. If dairy causes you digestive distress, forcing yourself to drink buttermilk for its liver benefits would be counterproductive, since chronic gut inflammation is itself a risk factor for liver problems.
Sodium content is another consideration. Some commercial buttermilk brands add salt during production, and excess sodium intake is linked to higher blood pressure and fluid retention, both of which can complicate liver disease in people who already have it. If you have existing liver problems, check labels and opt for low-sodium versions when possible.
Finally, buttermilk is not a treatment for established liver disease. The evidence discussed here relates to prevention or to very early-stage metabolic changes in animal models. If you have been diagnosed with fatty liver disease, cirrhosis, or any other liver condition, dietary changes should be part of a broader medical plan, not a substitute for one.
How Buttermilk Compares Within the Dairy Family
The UK Biobank study that tracked dairy subtypes is helpful for putting buttermilk in context. Fermented dairy products as a category showed stronger protective associations with liver outcomes than unfermented products, and low-fat dairy outperformed high-fat dairy. Buttermilk checks both boxes: it is fermented and typically low in fat. Cheese, despite also being fermented, did not show the same protective relationship in the Korean cohort study, possibly because its high fat and sodium content offset the benefits of fermentation.1PubMed. Intake of the different types of dairy products, genetic predisposition, and the risks of nonalcoholic fatty liver disease and cirrhosis: a prospective cohort study
Yogurt is the closest comparison to buttermilk in terms of composition, and it showed similarly favorable associations in the epidemiological data. The practical difference is that buttermilk contains more MFGM, the phospholipid-rich membrane fraction, because of the churning process. Whether that translates into a measurably larger liver benefit in real-world consumption is something no study has directly tested yet. For now, the reasonable take is that buttermilk sits alongside yogurt and kefir as one of the more liver-friendly dairy options, with a possible edge from its unique MFGM content that has not been fully quantified in human trials.