Constipation is often met with the same advice: drink more water, eat more fibre or try magnesium. Those steps can help, but they do not work for everyone. If you have already tried them, that does not mean you have failed to do the obvious things.

Constipation can have several contributors, including medicines, changes in bowel movement, difficulties with the muscles used to pass a stool, and other health conditions. Sometimes more than one factor is involved.

What about gut microbes?

Some microbes produce methane, a gas associated with slower movement through the bowel. It may be relevant for some people with constipation, but symptoms such as bloating or hard stools cannot by themselves tell us whether methane is involved.

Researchers are also exploring the protective mucus that lines the colon. In one 2026 study, two mucin-degrading microbes were more abundant in people with constipation. When the researchers put both microbes into germ-free mice, the mice developed constipation. That offers a possible explanation worth investigating, but it does not show that the same mechanism is the reason for an individual person's symptoms.

In particular, dry stools or a poor response to fibre or magnesium do not prove that your mucus layer is thin. We do not yet have an established “mucin-depletion” diagnosis based on those signs.

What is useful to do now?

If constipation persists, it is worth looking at the whole picture rather than simply adding more fibre or supplements. The right next step depends on your symptoms, medicines, eating pattern and health history. More fibre can be helpful for some people, while the type and amount may need adjusting for others.

Speak with your GP about persistent or changing bowel symptoms, particularly if they are new for you or come with other concerning changes. Personalised nutritional support can then help you work through the food and lifestyle side without assuming a single microbiome cause.

For the research and its limitations in more detail, read my practitioner-focused article.