Yogurts, the great allies of your gut microbiome

Although fermented milk products have existed for millennia—as evidenced by traces of lactic fermentation found in pottery dating back to 8000-7000 BC—it wasn’t until the early 20th century that Stamen Grigorov and Elie Metchnikoff identified a bacterium essential to yogurt production ¹.

Today, in most parts of the world, the term yogurt refers to a fermented milk product made through the combined action of two bacteria:

• Streptococcus thermophilus
• Lactobacillus bulgaricus.

These lactic acid bacteria work in symbiosis and are essential to yogurt production through the process of milk fermentation. It can be made from cow’s or sheep’s milk, plain or flavored, stirred or enriched with cream…
While recipes, spellings, textures, and pronunciations may differ, they all trace back to the Turkish root yoğurt, found in the verb “yoğurmak” meaning “to thicken”. Only skyr follows a slightly different tradition: originating in Norway and Iceland, it is a strained yogurt made from skim milk, with a denser texture. Very low in fat and particularly high in protein—about twice as much as regular yogurt—it has a particularly appealing nutritional profile ².

Beyond their differences, all of these yogurts share nutritional benefits worth exploring in more detail to better understand their effects on health, digestion, and microbiota.

They help make our gut a more hospitable place

The first benefit of yogurt is that it reshapes the population of microorganisms in our gut. This is because Streptococcus thermophilus and Lactobacillus bulgaricus are probiotics that help maintain the balance and diversity of the gut microbiota ^3,4.This diversity goes hand in hand with a healthy and well-functioning microbiota, which ensures good digestion and a stronger immune system.

They help protect us from minor colds

Thanks to the probiotics they contain, yogurts can support the gut’s immune defenses. Their bacteria help maintain a balanced gut microbiota, limit the growth of certain unwanted microorganisms, and strengthen the intestinal lining. Some studies also suggest improved regulation of the immune response and a reduction in certain digestive infections, but these effects vary depending on the product consumed, the strains it contains, and the individual ^5,6.
As a result, regular yogurt consumption could help lower the risk of gastrointestinal infections… and even common colds in older adults! One study has found that consuming 90 g of yogurt daily boosts the immune system and protects against infections ⁷!

They help fight diabetes

For several years now, scientists have observed that regular consumption of dairy products—particularly plain yogurt (mainly made from cow’s milk, typically 80 to 125 g per day)—is associated with a lower risk of developing type 2 diabetes. According to the International Diabetes Federation, type 2 diabetes mellitus currently affects around 11% of the world's population. This protective effect may occur through the gut microbiota, regardless of whether the yogurt is high-fat or low-fat ^8,9.

They help shed excess weight

Regular yogurt consumption has also been associated with less long-term weight gain compared with people who never eat yogurt ¹⁰. This may be partly explained by yogurt’s high protein content, which promotes satiety and helps better regulate appetite ¹¹.
Yogurt is also a good source of calcium—from milk—, which may play a role in metabolism. Some data suggest that calcium helps modulate the gut microbiota and strengthen the intestinal barrier, thereby limiting the inflammatory processes involved in obesity ¹².
Finally, results from the PREDIMED study indicate that daily yogurt consumption is also associated with lower abdominal obesity, further supporting the idea of a beneficial effect on body composition ¹³.

They help combat lactose intolerance

Yogurt is also a must-have for anyone dealing with lactose intolerance caused by cow’s milk. With fermentation, the bacterium Lactobacillus bulgaricus converts lactose into lactic acid, making it much easier to digest. This process helps restore the gut’s pH balance and reduces symptoms of digestive disorders such as constipation, bloating, and diarrhea, which can often cause abdominal pain ^14,15. Eat as much as you like—your digestive system will thank you!

They help keep our hearts healthy

Yogurt has another ace up its sleeve: it protects our cardiovascular system over the long term. Scientists have found that eating one to two yogurts a day reduces the risk of developing high blood pressure by 10% to 20% ¹⁶. They have reached similar conclusions regarding heart attacks and stroke-related mortality, specifically with whole-milk yogurt ^17,18.
 

They help us strengthen our bones

Daily yogurt consumption is associated with stronger bones, thanks to an increased bone density (+3 to 4%) and a reduced risk of osteoporosis (up to -39% in women and -52% in men) ¹⁹. These benefits seem to be linked to yogurt’s high calcium and protein content, and potentially its positive impact on the gut microbiota ^20,21.

Do they bring us closer to immortality?

Could yogurt actually extend our life expectancy? A study of a woman who lived to be 117 years old revealed a surprisingly “young” gut microbiota, associated with good overall health. Her regular consumption of yogurt may have contributed to the presence of beneficial bacteria such as Bifidobacterium ²².

More broadly, research shows that the microbiota plays a crucial role in aging by influencing immunity, inflammation, and overall health ²³. While these results are still preliminary and do not prove a direct link between yogurt and longevity… they’re still a good excuse to have another one, just in case science has a few more surprises in store for us!