Non-alcoholic fatty liver disease (NAFLD) affects approximately one in three UK adults, occurring when excess fat accumulates in the liver. Whilst weight loss remains the most evidence-based intervention, many people ask about the best fibre supplement for fatty liver as part of a comprehensive dietary strategy. Dietary fibre—particularly soluble types such as psyllium husk, inulin, and glucomannan—may support metabolic health by improving insulin sensitivity, cholesterol levels, and satiety. However, fibre supplements are not a cure for NAFLD and should complement, not replace, whole food sources and lifestyle modifications recommended by NICE and the NHS.

Understanding Fatty Liver Disease and Dietary Fibre

Non-alcoholic fatty liver disease (NAFLD) affects around one in four to one in three adults in the UK and occurs when excess fat accumulates in liver cells, unrelated to alcohol consumption. This condition ranges from simple steatosis (fat accumulation) to non-alcoholic steatohepatitis (NASH), which involves inflammation and potential scarring. Over time, NAFLD can progress to advanced fibrosis, cirrhosis, and hepatocellular carcinoma. Cardiovascular disease is the leading cause of death in people with NAFLD. Risk factors include obesity, type 2 diabetes, high cholesterol, and metabolic syndrome.

Dietary fibre may support NAFLD management as part of an overall dietary and lifestyle approach. Fibre is the indigestible portion of plant foods that passes through the digestive system, and it exists in two main forms: soluble and insoluble. Research suggests that adequate fibre intake may help improve metabolic risk factors such as insulin sensitivity, blood lipids, and body weight—all relevant to NAFLD management. However, evidence that fibre supplements directly reduce liver fat or inflammation in humans is limited, and weight loss remains the most effective intervention for improving liver outcomes.

The NHS recommends 30 grams (g) of fibre daily for adults, yet most UK residents consume only about 18 g. This significant shortfall may contribute to metabolic health issues, including fatty liver disease. Increasing fibre intake through diet should always be the first approach, with whole grains, vegetables, fruits, legumes, and nuts providing excellent sources. The NHS Eatwell Guide recommends basing meals on wholegrain starchy foods and consuming at least five portions of fruits and vegetables daily. When dietary intake proves insufficient or impractical, fibre supplements may offer additional support.

NICE guidance (NG49) on NAFLD emphasises lifestyle modification as the cornerstone of treatment, including dietary changes to achieve gradual weight loss. Weight loss of 7–10% or more of body weight is associated with greater improvements in liver steatosis and inflammation. Whilst fibre supplements are not established as a standalone treatment for fatty liver, they may form part of a comprehensive dietary strategy when used appropriately alongside other lifestyle modifications and under healthcare professional guidance.

How Fibre Supplements May Support Metabolic Health

Fibre supplements may benefit metabolic health through several interconnected physiological mechanisms, which in turn may indirectly support liver health. Soluble fibre forms a gel-like substance in the digestive tract, which slows glucose absorption and helps regulate blood sugar levels. This improved glycaemic control is particularly relevant for individuals with fatty liver disease, as insulin resistance frequently accompanies and exacerbates the condition. By moderating post-meal blood sugar spikes, fibre may reduce metabolic stress. However, clinical evidence that these effects translate into improved liver function tests or histology in NAFLD is limited.

The gut–liver axis represents another pathway through which fibre may influence health. Soluble fibre serves as a prebiotic, feeding beneficial gut bacteria that produce short-chain fatty acids (SCFAs) such as butyrate, propionate, and acetate. These SCFAs have anti-inflammatory properties in experimental models, and a healthy gut microbiome supported by adequate fibre intake may help maintain intestinal barrier integrity. Whilst these mechanisms are plausible, robust human outcome data demonstrating that fibre supplementation reduces liver inflammation or fibrosis in NAFLD are lacking.

Cholesterol metabolism is significantly affected by soluble fibre supplementation. Fibre binds to bile acids in the intestine, promoting their excretion and forcing the liver to utilise cholesterol to produce new bile acids. This process can lower circulating LDL cholesterol levels, which is beneficial as dyslipidaemia commonly coexists with fatty liver disease. Meta-analyses suggest that psyllium husk, in particular, may reduce total and LDL cholesterol by approximately 5–10% when taken regularly. Improvements in lipid profiles are important for cardiovascular risk reduction, which is a priority in NAFLD management.

Weight management support provided by fibre supplements should not be overlooked. Fibre increases satiety and promotes feelings of fullness, potentially reducing overall calorie intake. Since weight loss remains the most evidence-based intervention for reducing liver fat according to NICE guidance, any dietary strategy that supports sustainable calorie reduction may indirectly benefit liver health. However, fibre supplements should complement, not replace, a balanced, calorie-controlled diet rich in whole foods. Overall dietary patterns and weight loss have the strongest evidence for NAFLD improvement.

Types of Fibre Supplements

Psyllium husk (ispaghula, Plantago ovata) is one of the most extensively studied fibre supplements and is widely available in the UK under various brand names, including Fybogel. This soluble fibre supplement absorbs water to form a viscous gel, which slows digestion and promotes regular bowel movements. Clinical evidence suggests psyllium may improve lipid profiles and glycaemic control—both relevant to metabolic health in NAFLD. Typical dosing ranges from 5–10 g daily, divided into two or three doses. Always follow the product label instructions and take each dose with at least one to two full glasses of water (approximately 250 ml or more per dose) to prevent choking or intestinal obstruction. Separate psyllium from other medicines by at least one to two hours, or as advised by your pharmacist or product leaflet, as it may interfere with absorption of certain drugs.

Inulin and fructo-oligosaccharides (FOS) are prebiotic fibres extracted from chicory root, Jerusalem artichokes, and other plant sources. These soluble fibres resist digestion in the upper gastrointestinal tract and reach the colon intact, where they selectively stimulate beneficial bacteria growth. Some research indicates that inulin supplementation may improve metabolic parameters, though evidence for direct effects on liver fat in humans remains preliminary. Inulin is generally well-tolerated at doses of 5–10 g daily, but it commonly causes bloating or flatulence, particularly when starting supplementation or in individuals with irritable bowel syndrome (IBS) or following a low-FODMAP diet. If you have IBS or are sensitive to FODMAPs, consider starting with a lower dose or choosing a gentler alternative such as psyllium or methylcellulose.

Glucomannan (Amorphophallus konjac) is a highly viscous soluble fibre derived from the konjac plant root. It has exceptional water-absorbing capacity, expanding up to 50 times its weight. This property makes glucomannan particularly effective for promoting satiety and supporting weight management efforts. The European Food Safety Authority (EFSA) has approved health claims for glucomannan related to weight loss when 3 g per day is taken in three 1 g doses before meals with one to two glasses of water, as part of an energy-restricted diet. Important safety note: glucomannan poses a choking risk if not taken with adequate fluid. Swallow each dose with at least one to two full glasses of water. Do not use glucomannan if you have difficulty swallowing (dysphagia) or any narrowing of the oesophagus or gastrointestinal tract. Avoid taking glucomannan immediately before bedtime.

Methylcellulose and wheat dextrin are semi-synthetic or processed fibre supplements that offer gentler alternatives for individuals sensitive to natural fibres. Methylcellulose is non-fermentable, producing less gas than fermentable fibres, whilst wheat dextrin dissolves completely in liquids without altering texture. These options may suit those who experience significant bloating with other fibre types, though they may offer fewer prebiotic benefits than naturally fermentable fibres. If you have coeliac disease, check the product label to confirm that wheat dextrin products are certified gluten-free.

Choosing the Right Fibre Supplement

Individual tolerance and digestive comfort should guide fibre supplement selection. Begin with a low dose (approximately one-third of the target amount) and gradually increase over two to three weeks to allow the gut microbiome and digestive system to adapt. This gradual approach minimises common side effects such as bloating, cramping, and excessive flatulence. If one type of fibre causes persistent discomfort, consider switching to an alternative rather than abandoning supplementation entirely.

Soluble fibres have more evidence for improving metabolic risk factors such as blood lipids and glycaemic control, which indirectly supports NAFLD management, compared to insoluble fibres, though both types contribute to overall health. For fatty liver disease specifically, prioritise supplements containing psyllium, inulin, or glucomannan, as these have the most relevant research supporting metabolic benefits. Check product labels carefully for fibre content per serving, ingredient sources, and any additional additives. Also review labels for added sugars, sweeteners, and sodium content; choose sugar-free options if you have diabetes or are managing your weight.

Quality and regulatory considerations matter when selecting supplements. In the UK, food supplements are regulated by the Food Standards Agency (FSA) and must comply with food safety legislation, though they are not subject to the same rigorous testing as medicines. Look for products from reputable UK manufacturers that provide clear information about fibre content per serving, ingredient sources, and any additional additives. Be cautious of products making exaggerated health claims about "curing" or "reversing" fatty liver disease, as fibre supplements are not established as a cure for NAFLD.

Cost-effectiveness and practicality also influence long-term adherence. Generic psyllium husk powder typically offers excellent value compared to branded products or capsules. Powders generally provide more fibre per serving at lower cost than capsules, though capsules offer convenience for those who travel frequently or dislike the texture of fibre drinks. Consider your lifestyle, budget, and preferences when making a selection, as the best supplement is ultimately the one you will take consistently as part of a comprehensive dietary approach.

Safety Considerations and NHS Guidance

Fibre supplements are generally safe for most adults when taken as directed with adequate fluid intake. However, several important precautions warrant attention. Always consume fibre supplements with at least one to two full glasses of water or other liquid (approximately 250 ml or more per dose) to prevent choking, oesophageal obstruction, or intestinal blockage. Follow the specific product leaflet instructions for fluid volumes. Take fibre supplements at least one to two hours before or after medications, or as advised by your pharmacist or product information, as fibre can interfere with the absorption of certain drugs, including some diabetes medications (such as metformin), thyroid hormones (levothyroxine), and cardiac glycosides. If you take regular medications, consult your GP or pharmacist before starting fibre supplementation.

Certain medical conditions require caution or contraindicate fibre supplement use. Do not use fibre supplements if you have a history of intestinal obstruction, faecal impaction, oesophageal narrowing or strictures, difficulty swallowing (dysphagia), or gastrointestinal strictures. Individuals with inflammatory bowel disease (IBD) should seek medical advice before using fibre supplements, particularly during active disease or if stricturing disease is present. Those with diabetes should monitor blood glucose levels closely when initiating fibre supplementation, as improved glycaemic control may necessitate medication adjustments. If you are pregnant, breastfeeding, or considering fibre supplements for a child, consult your GP or pharmacist before use. If you experience severe abdominal pain, vomiting, or difficulty passing stools after taking a fibre supplement, seek immediate medical attention.

NHS guidance emphasises whole food sources as the preferred method for increasing fibre intake. The NHS Eatwell Guide recommends basing meals on wholegrain starchy foods, consuming at least five portions of fruits and vegetables daily, and including pulses and legumes regularly. Fibre supplements should complement, not replace, these dietary foundations. For individuals with confirmed NAFLD, NICE guidance (NG49) recommends that primary care clinicians calculate a fibrosis risk score such as FIB-4 or the NAFLD fibrosis score, using age-adjusted thresholds. For those at intermediate or high risk of advanced fibrosis, consider the Enhanced Liver Fibrosis (ELF) test as a second-line assessment (NICE DG27). Refer patients at high risk of advanced fibrosis to specialist hepatology services. Personalised nutritional advice from a dietitian may also be beneficial.

Alcohol intake should be addressed in people with NAFLD. Follow the UK Chief Medical Officers' low-risk drinking guidelines (no more than 14 units per week, spread over three or more days). Some individuals may be advised to abstain from alcohol entirely, depending on their liver health and other risk factors. Discuss your alcohol intake with your GP.

When to contact your GP: Seek medical review if you experience unexplained weight loss, persistent abdominal pain, jaundice (yellowing of skin or eyes), significant fatigue, abdominal swelling (ascites), ankle swelling, gastrointestinal bleeding or black stools, confusion, easy bruising, dark urine or pale stools, or severe itching (pruritus), as these may indicate liver disease progression requiring specialist assessment. Regular monitoring through your GP is essential for anyone with diagnosed fatty liver disease, typically including periodic blood tests to assess liver function and metabolic parameters. Remember that whilst fibre supplementation may support overall metabolic health, it should form part of a comprehensive lifestyle approach including weight management, regular physical activity, and, where appropriate, management of underlying conditions such as diabetes or hyperlipidaemia.

Reporting side effects: If you experience a suspected side effect from a fibre supplement, you can report it via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or by searching for 'MHRA Yellow Card' in the Google Play or Apple App Store.

Frequently Asked Questions