7 fibre-rich foods for gut health: Harvard-trained gut doctor shares his recommendations

A healthy digestive system depends on more than simply avoiding junk food or eating at regular intervals. The type and variety of fibre in the diet also matter because different fibres can support bowel regularity and interact differently with gut microbes. Fibre-rich plant foods can also contribute to overall heart and metabolic health. Harvard's Nutrition Source recommends getting fibre from a variety of whole grains, fruits, vegetables, legumes, nuts and seeds rather than focusing on a single food. Harvard-trained gut doctor Dr Saurabh Sethi has shared seven fibre-rich foods he recommends for supporting gut health in his latest Instagram post.

Chia seeds

Chia seeds are an easy way to increase daily fibre intake without significantly changing meals. Dr Sethi points out that two tablespoons provide about 10 grams of fibre. Harvard Health's Nutrition Source puts the figure at around 11 grams per 28-gram serving, along with protein and unsaturated fats. Chia contains both insoluble fibre and mucilage, a type of soluble fibre that absorbs water.

Lentils

Lentils are another fibre-rich option that also supplies plant protein. According to Dr Sethi, one cooked cup provides roughly 15 grams of fibre. Harvard notes that lentils contain both soluble and insoluble fibre, as well as resistant starch and prebiotic components that can be used by gut bacteria.

Raspberries

A cup of raspberries provides about 8 grams of fibre, according to Dr Sethi, while also supplying polyphenols. These plant compounds can interact with gut microbes. Berries are also among the fruits that contribute fibre and a range of plant compounds to the diet, making them useful additions to a varied eating pattern.

Avocado

One avocado can provide around 10–13 grams of fibre, Dr Sethi says, while also supplying predominantly monounsaturated fats. Harvard's Nutrition Source lists a medium avocado as containing about 10 grams of fibre, with most of its fat being monounsaturated.

Oats

Oats stand out for their beta-glucan, a soluble fibre that can be fermented by gut microbes. Harvard notes that beta-glucan can slow digestion and bind cholesterol-rich bile acids, supporting cholesterol management. The fibre also contributes to bowel regularity.

Pears

A medium pear contains roughly 5–6 grams of fibre, according to Dr Sethi. Keeping the skin on is particularly useful because fruit skins contain fibre. Harvard also identifies pears and other fruits with edible skins as sources of insoluble fibre, which can help food move through the digestive system.

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A post shared by Saurabh Sethi MD MPH | Gastroenterologist (@doctor.sethi)

Chickpeas

Chickpeas round out the list, with around 12 grams of fibre in a cooked cup, according to Dr Sethi. They also provide protein and contain soluble fibre such as raffinose, which can be fermented by beneficial gut bacteria. Harvard notes that this process produces short-chain fatty acids such as butyrate.