Tiredness and bloating: the role of the gut and habits that help

Reading time: 7 minutes

Have you noticed that, despite your efforts, your stomach sometimes seems to “do its own thing”? Heaviness after lunch, a bloated stomach at the end of the day, energy that drops around 2 pm: these feelings often go together, and they're very common. Here's what happens in the gut, the myths to forget, and the simple habits that help.

In short

• Bloating is one of the most common digestive discomforts. It mainly comes from the fermentation of certain foods and how the gut perceives it.
• The gut and brain are in constant dialogue: stress, sleep and diet affect both.
• Good reflexes: eat more slowly, increase fibre gradually, move after meals, get enough sleep. Vitamin C contributes to the reduction of tiredness and fatigue.

Bloating: very common, rarely serious

A large survey in 33 countries by the Rome Foundation, a reference in gastroenterology, shows that more than 40% of adults have so-called “functional” digestive disorders, with no identified disease, such as bloating or irregular bowel movements (Sperber et al., 2021).

Bloating has several causes, often combined (Lacy et al., 2021):

• Fermentation: certain fibres and sugars (onion, garlic, pulses, wheat, apples, dairy for some people) are fermented by bacteria in the colon, which produces gas.
• Swallowed air: eating fast, talking while eating, chewing gum or drinking fizzy drinks.
• A more sensitive gut: in some people, a normal amount of gas is felt as discomfort.
• Slower transit: lack of movement, days spent sitting, a change of routine.

The dialogue between gut and brain

The gut is often called our “second brain”: its wall contains millions of neurons, and researchers talk about the gut-brain axis to describe the constant exchanges between the two (Cryan et al., 2019). Stress can slow down or speed up digestion, and an uncomfortable stomach in turn weighs on mood and energy.

A myth to correct. You often read that “95% of serotonin, the happiness hormone, is made in the gut”. It's true that about 90% of the body's serotonin is produced in the gut (Yano et al., 2015). But that serotonin is mainly used for digestion: it doesn't reach the brain. So on its own, it doesn't create our good mood.

A large share of immune cells is also found in the gut wall. We explain this in Probiotics and immunity in autumn.

The microbiota, in real numbers

You may have read that your gut hosts “100 trillion bacteria, ten times more than your cells”, weighing “two kilos”. These old figures have been revised: an adult hosts about 38 trillion bacteria, roughly as many as human cells, weighing about 200 grams (Sender et al., 2016).

Did you know? If you unfolded your small intestine, its inner surface, with all its folds, would reach about 30 m², the size of a small studio flat (Helander and Fändriks, 2014). It's a huge area of exchange with what we eat.

Why we feel tired

Tiredness has a thousand causes: too little sleep, stress, lack of light in winter, meals that are too heavy or too sugary, a sedentary lifestyle. A large meal mobilises digestion and can make the early-afternoon slump worse.

As for nutrients, several vitamins and minerals contribute to the reduction of tiredness and fatigue, including vitamin C, vitamin B6, vitamin B12, iron and magnesium (Regulation (EU) No 432/2012). Our body doesn't store vitamin C: a regular intake counts.

Tiredness that lasts several weeks for no obvious reason is worth discussing with your doctor (see the FAQ).

Everyday habits that help

• Eat more slowly and chew well: you swallow less air, and your stomach has time to send the fullness signal.
• Increase fibre gradually: fruit, vegetables, pulses and whole grains feed the microbiota, but a sudden increase can cause gas in the first few days.
• Identify the foods that bother you: for some people, cutting back for a few weeks on foods rich in fermentable sugars (called FODMAPs) relieves bloating (Halmos et al., 2014). Ideally do this with a doctor or dietitian, so as not to restrict your diet too much.
• Move after meals: a 10 to 15-minute walk helps digestion.
• Drink water regularly and limit fizzy drinks.
• Protect your sleep: regular hours help digestion too.

What about probiotics?

Not all probiotics are equal: each strain has its own characteristics, and what is observed for one doesn't necessarily apply to another. The most studied belong to the Lactobacillus and Bifidobacterium families. To choose well, read our guide What are probiotics?

To reach the gut alive, these bacteria first have to get through stomach acid. That's why the 4 strains in our Liquid Probiotic are microencapsulated: a thin coating helps them make the journey.

The liquid format has a simple advantage: nothing to swallow. A 15 ml serving is drunk as a shot or diluted in a glass of water or juice. It provides 10 billion CFU, 50 mg of L-glutamine and 80 mg of vitamin C, which contributes to the reduction of tiredness and fatigue and to the normal function of the immune system. A 500 ml bottle lasts 33 days.

A morning ritual

In our daily lives, between school, work and running the home, there's no time for complicated protocols. Here's a simple ritual to adopt:

1. A large glass of water when you wake up, plain or with a dash of lemon.
2. Your serving of Liquid Probiotic, in the morning on an empty stomach or 30 minutes before breakfast.
3. A breakfast with fibre: oats, fruit, wholemeal bread.

What our customers say

“The taste is just great, I'll be buying it again, I recommend it without hesitation.”
Andi, Liquid Probiotic, review published on our Amazon store

“It's easy and pleasant to take: liquid with a nice lemon-sweet taste.”
Philemon, Liquid Probiotic, review published on our Amazon store

“Very good product.”
Sarah, Liquid Probiotic, review published on vitamoon.fr

Frequently asked questions

I already eat yoghurt or kefir, is that enough?

The cultures in dairy products have their place in a varied diet. Their strains and quantities aren't always stated: a supplement specifies the number of CFU and the name of each strain.

Will I feel bloated at the start of the course?

Some people experience a little gas or mild bloating in the first few days, while the gut gets used to it. If the discomfort lasts or worries you, stop the course and ask a healthcare professional for advice.

What's the ideal length for a course?

One bottle corresponds to a 33-day course, at 15 ml a day. You can repeat it, for example when the seasons change.

When should you see a doctor about bloating or tiredness?

See a doctor if bloating comes with severe pain, blood in the stools, unexplained weight loss, vomiting or fever, if it appears after age 50, or if tiredness lasts several weeks with no explanation.

Can I take it if I'm pregnant, breastfeeding or on medication?

Ask your doctor or pharmacist for advice first.

Further reading

• What are probiotics?
• Probiotics and immunity in autumn
• The secret to a light stomach when travelling
• Why you (still) fall ill in February

Sources

• Sperber A.D. et al. (2021). Worldwide prevalence and burden of functional gastrointestinal disorders, results of Rome Foundation Global Study. Gastroenterology, 160(1), 99-114.
• Lacy B.E., Cangemi D., Vazquez-Roque M. (2021). Management of chronic abdominal distension and bloating. Clinical Gastroenterology and Hepatology, 19(2), 219-231.
• Cryan J.F. et al. (2019). The microbiota-gut-brain axis. Physiological Reviews, 99(4), 1877-2013.
• Yano J.M. et al. (2015). Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell, 161(2), 264-276.
• Sender R., Fuchs S., Milo R. (2016). Revised estimates for the number of human and bacteria cells in the body. PLoS Biology, 14(8), e1002533.
• Helander H.F., Fändriks L. (2014). Surface area of the digestive tract – revisited. Scandinavian Journal of Gastroenterology, 49(6), 681-689.
• Halmos E.P. et al. (2014). A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology, 146(1), 67-75.
• Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods.