How does micronutrient deficiency affect gut microbes?

You aren’t the only one who gets nourished by the food you eat – the good bacteria in your gut also benefit from it, thanks to the micronutrients found in your food. An article in the Sanford Burnham Prebys news page reported that a deficiency in vitamins and minerals harms your gut microbiota.

This is particularly worrisome given that one out of every four people in the world does not have all of the micronutrients they need. And while researchers have gathered much knowledge about the effects of vitamin and mineral deficiency on humans, they know far less about the corresponding outcomes on the bacterial population that live in their guts.

Gut microbes are significant contributors to the health of their hosts and the prevention or development of diseases. Sanford Burnham Prebys researchers, therefore, set out to determine the side effects of insufficient micronutrients on the gut bacteria of mice.

The results confirmed the vital role of micronutrients in the proper growth and development of the human body. These vitamins and minerals are used to make enzymes, hormones, and other important biological molecules.

Small amounts of these substances are all that is required for the body to function correctly. But if that minuscule amount gets depleted, the result is often severe. (Related: Gut bacteria “signatures” predict how the body will respond to poor food choices, predicting risk for diabetes, heart disease.)

Micronutrient deficiency weakens good gut bacteria

In the SBP animal model, a wide variety of bacterial strains found in the human gut were cultured in the guts of mice. The animals underwent different diets throughout the trial.

During the first part, the mice received a diet with enough micronutrients. Then they would be given food that lacked one of four micronutrients: Folate, iron, vitamin A, or zinc.

Finally, the animals would get their original diet back to replenish the deficient micronutrient. The researchers examined the microbial RNA and DNA in the feces of the animals to determine the effect.

Out of the four micronutrients tested, vitamin A exerted the biggest effect on gut bacteria. It affected both the structure of the bacterial community and the activity of genes.

Vitamin A also encouraged the population of Bacteroides vulgatus to flourish. This strain of bacteria is positively connected to the postnatal growth of its host. A deficiency in the vitamin decreased the amount of these beneficial bacteria.

Vitamin A, the micronutrient for you and your gut microbes

Iron, folate, vitamin A, and zinc deficiencies are some of the most serious concerns for public health. Children and pregnant women in developing countries are especially vulnerable to these deficiencies.

Vitamin A deficiency, in particular, is a problem in one out of every two countries in the world. This micronutrient contributes to the growth, immune function, and vision of people.

Insufficient amounts cause preventable blindness in children. For pregnant women, it can lead to night blindness and maternal mortality. It also weakens the immune system, making you more vulnerable to infection.

To combat this, the World Health Organization (WHO) suggests supplementing with large amounts of vitamin A. The researchers, however, suggest that people should also regulate the number of vitamins they consume each day.

“However, our results provide a rationale and a preclinical method for examining whether current vitamin A dosing regimens, and by extension other critical micronutrients, have unintended and deleterious effects on the developing gut microbiota of undernourished children, whose healthy growth such treatments are intended to promote,” said Andrei Osterman, the SBP researcher in charge of the study.

Find out about the best foods to keep your micronutrient levels topped off at

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