eating archivos - Elisa Divulga

Do you have trouble going to the bathroom? Do you feel more bloated?
These could be some of the problems that come with summer and are related to our gut microbiota.

What is Gut Microbiota?

Gut microbiota is the group of microorganisms living in our intestines, previously known as “intestinal flora.” And it’s not just bacteria; other little creatures also live in our gut, such as viruses, fungi like yeast, and special cells called archaea.

Does it Serve a Purpose?

Lots of them. Gut microbiota works a lot for us. In fact, when this community in our intestines is disrupted, we start having problems.

To name just a few tasks, our gut microbiota is responsible for:

Digesting and fermenting parts of food that we couldn’t digest in the stomach to extract energy and absorb more nutrients.
Producing and releasing enzymes, hormones, and vitamins like vitamin K.
Controlling metabolism.
Fighting off other microorganisms that could cause infections (pathogens).
Supporting the immune system.

Thanks to all these functions, many organs and systems in our body work properly, such as muscles and even the brain.

Why Are All These Critters in My Intestines?

The answer is simple: because we don’t live in a sterile environment. We are surrounded by microorganisms from the moment we are born. Actually, a baby’s microbiota varies depending on whether they are born vaginally or by cesarean section, and whether they are fed breast milk or formula.

The environment is different for each one of us. That’s why not everyone has the same microorganisms or in the same amounts. Our microbiota is unique, like a fingerprint.

What Affects Our Gut Microbiota?

Each of us has a variety of different microorganisms in our intestines, and they vary depending on many factors, including:

Diet.
Physical exercise.
Sleep.
Stress.
Whether you live in the countryside or the city.
Whether you are taking medication (especially antibiotics).

How Does Summer Affect It?

As we’ve seen, many factors affect our gut microbiota and its ability to perform all those beneficial tasks. So, you can imagine that, if during the summer we change our diet, exercise routine, and the quality of our sleep, the microorganisms living in our intestines won’t be too happy.

We eat more junk food, snack more between meals, and drink more sugary drinks and alcohol. Plus, in summer, we stay up later and sleep worse due to the heat. And on top of that, we become more sedentary.

Additionally, changes in the environment and travel (especially long trips involving time zone changes) can also affect us. Not to mention, many people don’t feel comfortable using the bathroom when they’re not at home.

That’s why you might have noticed feeling more bloated, having more gas, or experiencing constipation these past months.

And let’s not forget about seasonal changes. Many things in our body change with the seasons. Remember, we follow biological rhythms, such as circadian rhythms, which last 24 hours.

Depending on the time of day or the season of the year, and therefore the environmental conditions (light, temperature, humidity, pollution…), things like our hormone levels or digestion can change.

Research on 24-hour cycles and their effect on the microbiota is more robust than studies on microbiota changes by season, as these often relate to the availability of certain types of foods.

However, let’s be cautious with the information because, as I said, there are still many things we don’t know about this community of critters living in our gut.

But What About the Heat?

Temperature is part of the environment, and there are already plenty of studies on heat and its effects on the gut microbiota of various animal species. And yes, there is also research on how heat affects human gut microbiota.

Heat is considered a stressor, and we already know that stress is not good for gut microbiota.

In a study published less than three months ago, researchers found that exposing athletes to heat, a common practice to improve sports performance, altered their gut microbiota. The conclusion of this and other studies (which I’ve linked in the references) is that the more heat there is, the less blood reaches our intestines, meaning less oxygen there.

According to various studies, high temperatures prevent microorganisms from functioning properly and cause dysbiosis, which is a variation in the microbiota balance. Two consequences of dysbiosis are inflammation and changes in permeability, which is the ability of our intestines to allow nutrients (and other things) to pass into the blood.

These changes in gut microbiota can lead to certain disorders and make it easier to get infections. Dysbiosis has been linked to chronic diseases like obesity, diabetes, metabolic disorders, inflammatory bowel disease, autoimmune diseases, and even mental health conditions.

We still have a lot to learn about gut microbiota, but it seems that high temperatures stress both our nervous system and immune system. This sends signals to our intestines, through neurotransmitters and hormones, telling the community of critters that something is wrong.

Dehydration and Its Effects

Additionally, heat also causes dehydration. And since the body is wise, it has mechanisms to save water, such as producing less urine and making stools drier.

It’s been observed in animals that chronic dehydration alters the composition of gut microbiota, meaning the types of bacteria we have. There are even fewer immune cells in the intestines.

But again, we need more research, especially in humans.

How Can We Support Our Gut Microbiota?

Eat a healthy diet: As I always say, prioritize plant-based foods like fruits, vegetables, legumes, whole grains, and nuts. The more of these, the better. Partly because they contain fibre, which is a prebiotic, meaning food for bacteria.
Avoid foods high in fat and loaded with sugar and/or salt: These types of foods, like ultra-processed ones, encourage the growth of bad bacteria.
Eat probiotic foods, meaning foods that contain live good bacteria like yoghurt, kefir, and fermented foods.
Exercise regularly.
Avoid taking antibiotics without a prescription.
Take care of your mental health.