Gastroenteritis, often referred to as the “stomach flu,” is an inflammation of the lining of the stomach and intestines. This condition is typically characterized by acute symptoms such as diarrhea, vomiting, and abdominal pain. The question of whether yogurt is beneficial during this time is complex, as its potential to aid recovery is conditional on the stage of the illness and the individual’s digestive tolerance.
How Probiotics in Yogurt Aid Recovery
Gastroenteritis, especially when caused by viruses or bacteria, disrupts the delicate balance of the gut microbiome. The resulting inflammation and diarrhea cause a significant loss of beneficial bacteria, which can prolong symptoms and delay the return to normal digestive function.
Yogurt delivers probiotics, which are live, active cultures that help restore the microbial community. Strains like Lactobacillus and Bifidobacterium are commonly found in yogurt and are the primary agents of benefit. Introducing these organisms helps repopulate the gut, allowing the microbiota to regain its protective and digestive functions.
Beneficial bacteria can help shorten the duration of acute diarrhea, sometimes by about 25 hours. These organisms compete with harmful pathogens for nutrients and attachment sites on the intestinal wall. They also produce short-chain fatty acids, which nourish the cells lining the colon, supporting the gut’s natural barrier function and normalizing stool consistency.
The Importance of Lactose Tolerance During Illness
While the probiotics in yogurt are helpful, the dairy component introduces a complication: lactose. Lactose is the natural sugar in milk, requiring the enzyme lactase, produced in the small intestine, for proper digestion. Gastroenteritis causes inflammation and damage to the intestinal lining, which can temporarily reduce lactase production.
This temporary reduction is known as transient lactose intolerance, which can occur even in individuals who normally digest dairy. When undigested lactose reaches the large intestine, bacteria ferment it, causing gas, bloating, abdominal pain, and an osmotic effect that worsens diarrhea. Consuming full-dairy yogurt during the acute phase of illness may inadvertently exacerbate symptoms.
If a person has severe watery diarrhea, it is best to initially avoid full-lactose products. The intestinal brush border, where lactase is produced, is highly susceptible to damage during a gut infection. Avoiding lactose allows the lining time to heal and enzyme production to return to normal levels, typically within a few weeks.
Selecting the Best Yogurt and Timing Consumption
Careful selection and timing are necessary to maximize yogurt’s benefits while minimizing the risk of worsening symptoms. The most suitable yogurt explicitly states it contains “live and active cultures” on the label. This designation ensures the product has a sufficient quantity of beneficial bacteria that survived the fermentation process.
The ideal choice is plain, unsweetened yogurt, since high levels of added sugar can worsen diarrhea. If lactose intolerance is a concern, Greek yogurt is a better option because the straining process removes much of the lactose. Alternatively, lactose-free yogurts or fermented milk products like kefir, which are generally well-tolerated, can be used.
Yogurt should be introduced only after acute symptoms, such as frequent vomiting, have subsided and the individual can tolerate bland solid foods. It is best used during the recovery phase, not as a treatment for the initial sickness. Beginning with small amounts allows the body to test its tolerance, ensuring a smoother transition back to a normal diet.