Gut bacteria and weight gain? SIBO, candida, and constipation

Can gut bacteria make you gain weight? Can you really blame your bacteria for your weight? The simple answer to that is yes!


The balance of your gut bacteria is very strongly linked with obesity and metabolic disturbances. People visiting a nutritionist often present with 'SIBO', small intestinal bacterial overgrowth, and unexplained weight gain. Often together with constipation, clients will often complain of bloating, wind, and weight that they can’t seem to shift even when eating nothing but lettuce; and/or instant weight gain when they eat carbohydrates.

'Candida', or yeast overgrowth, can also cause weight gain. Sometimes it can feel more like water retention, but overall, the cravings for carbohydrates or sugars can sabotage all efforts to lose weight and cause a real imbalance in the diet. Sugar and antibiotics are generally the cause of excessive yeast in the first place, although simply cutting out everything sugary and yeast-based, and surviving off meat and veg, is not recommended.

The weight gain link with constipation tends to be twofold. One, chronic constipation causes SIBO, and two, it causes general gut dysbiosis (imbalanced gut bacteria) and general water retention.

A third cause is bacteria directly. Akkermansia muciniphila bacteria is associated with weight, and the balance of some other bacteria (Firmicutes and Bacteroidetes) is linked with weight gain. This is often seen in so many patients' and clients' stool tests. This balance is affected by your diet and lifestyle, in particular a low or high fibre diet. Your bacteria can also affect how much energy you absorb from your food and produce chemicals that help you feel full.

So, when you think you’re simply eating the wrong foods and giving in to temptation, it could actually be the gut flora (and your endocrine/hormonal system) that is creating cravings and an increased appetite, creating a vicious cycle.

It's not always about simply restricting. Your restricting may even lead to cravings for the wrong foods, which may create unbalanced gut bacteria in the first place. Address your gut, address your diet, and address your hormone system (and inflammation), and you give yourself the best chances of effortless and long-term weight management.

Refined and unrefined foods

Eat unrefined foods - always. Refined foods are flours (white being the most refined, whole grain being the least). 'Flour foods' seem to drive hunger for carbohydrates and can create cravings. Moving away from eating just grains (rice, rye, wheat, etc) - or eating them in their whole form only (not always easy to get hold of in the UK) - and introducing a lot more starchy foods such as potato (small and not baked), sweet potato, root vegetables, and peas and beans is the solution.

It's hard to overeat these foods, and they all make your gut flora very happy indeed, by feeding and promoting the growth of the weight loss type of bacteria.

Protein and some healthy fats help manage sugar cravings and always ensure you are hydrated. This is often mistaken for cravings or hunger.

What to do next?

If constipation is not easily shifted by a change in diet and hydration, and you feel that it is causing you weight gain, then it's likely that something a bit more fundamental is going on.

We can help you get to the bottom of it, and have extensive experience with chronic, persistent constipation. From our decades of experience, we have developed a four-step gut program that we will walk you through, which takes around three to six months.

Establishing whether you have troublesome gut bacteria is the first thing to do. Simply guessing will lead you around the houses, and lead to a loss of valuable time and life quality. 

To find out if gut bacteria causing your weight gain, fill in this two-minute form for your free health review. If you'd like to get in touch, you can send me a message via my profile.

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

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London W1H & NW6
Written by Linda Albinsson, Advanced Gut Health Nutrition Clinic
London W1H & NW6

Linda Albinsson is a highly experienced and qualified nutritionist specialising in areas of the microbiome, gut health, inflammatory conditions (skin, cardiovascular, pain and joint) and others

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