Vitamins, Calcium, Iron – What Are You Doing With my Intestines?
Dietary supplements can change the composition of the gut microbiota. What this means, however, needs to be researched in further studies.
The essentials in brief:
- Dietary supplements can influence the composition of the intestinal flora in a wide variety of ways.
- Studies show that additional vitamins, calcium, magnesium, or iron have an influence on the composition of intestinal bacteria.
- Anyone who suffers from diseases of the intestine, especially inflammatory changes such as Crohn’s disease or ulcerative colitis, should not take dietary supplements without consulting a doctor.
- A gut-friendly diet is always helpful for healthy people.
Dietary supplements affect the intestinal flora
A research team from Kiel was able to show that changes in the composition of the intestinal bacteria in type 2 diabetes are mainly related to obesity and the consumption of dietary supplements and medication and less to diabetes.
Medicines are taken regularly (such as antihypertensive agents, pain relievers, antidepressants, and antidiabetic drugs), and also dietary supplements have an influence on the intestinal microbiome (intestinal flora). In dietary supplements, it is magnesium, vitamins, calcium, and, above all, iron that change the composition of the intestinal bacteria.
This is particularly important for people with gastrointestinal diseases such as Crohn’s disease and ulcerative colitis and an unstable intestinal flora. A study has shown that the additional administration of iron, whether as a tablet or intravenously, significantly influences the composition of the intestinal flora.
In the future, the researchers hope to understand more precisely what these changes actually cause in the intestinal microbiome and which bacteria (see below) are the key players in order to be able to intervene specifically and thus influence the respective disease.
What should you watch out for?
If you have conditions like Crohn’s disease or ulcerative colitis, have recurring diarrhea, or have bowel problems, it is important to discuss these with your doctor before using any supplements. Be sure to ask during the conversation about a dosage that makes sense for you. For example, excessive amounts of magnesium can not only change the composition of the intestinal bacteria but also lead to diarrhea and gastrointestinal problems. Possible interactions with medication should also be considered.
What can you do for your intestinal bacteria yourself?
- Only eat small amounts of foods that cause constipation or have a laxative effect (e.g. certain spices).
- Drink enough.
- Eat – as far as you can tolerate them – high-fiber plant-based foods, i.e. whole grain products, oatmeal, and vegetables, but also fruit. Foods with natural inulin or oligofructose (special water-soluble fiber) such as legumes, chicory, artichoke, salsify, leek, onions, garlic, or asparagus can be helpful. Resistant starch (contained in potatoes, pasta, rice from the day before) also acts like fiber.
- Flax seeds and chia seeds can also have a positive effect, but the amounts should be limited to 20 or 15 grams per day.
- Sour milk products from the refrigerated shelf such as yogurt, kefir, ayran, lassi, or curd milk, but also lactic-acid fermented beans, carrots, sauerkraut, or Asian kimchi have a beneficial effect on the intestinal flora and thus possibly also on the immune system.
- So-called probiotic bacteria have no proven health-promoting effect in healthy people.
- Only take antibiotics when you really need them. Discuss this with your doctor.
- Avoid stress, get enough sleep, and exercise as much as possible.
What do intestinal bacteria do?
There are around 1.3 times as many bacteria in the intestine as there are cells in the human body. This so-called microbiota is involved in many processes such as digestion, the production of vitamins, and the defense against pathogens. 99% of the intestinal flora consists of four families of bacteria: Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria.
Above all, these break down indigestible carbohydrates (fiber), resulting in short-chain fatty acids (mainly acetic, propionic, and butyric acid), which are absorbed and metabolized by the cells of the intestinal wall. Their exact physiological significance is not yet known; in any case, they also stimulate intestinal peristalsis (bowel movement).
It is assumed that the loss of these symbiotic bacteria – and thus a change in their composition – promotes the development of allergies.
New research indicates that there is a connection between the composition of the intestinal flora and diseases of the brain (“gut-brain axis”). Animal experiments have also shown that a magnesium deficiency in mice led to changes in the intestinal flora and presumably led to depression. There is still a considerable need for research here