A 2022 Cochrane review of 24 randomized trials found a possible reduction in acute upper respiratory infections with probiotics. The evidence was low certainty, with a relative risk of 0.76.
Yogurt can provide protein and nutrients, and some varieties contain live cultures. But changes in immune-cell activity or self-reported symptoms do not show that yogurt prevents infection. That distinction matters.
Label check: Nutrition Facts can show protein and added sugars per serving, but it generally does not identify a probiotic strain or establish a clinically effective probiotic dose.
When researchers assess a health claim, confirmed infections, illness duration, and hospitalizations matter more than a lab-measured change in immune-cell activity. A 2021 meta-analysis of 22 randomized trials involving 10,190 participants reported about a 19% lower rate of respiratory infections with fermented dairy. The relative risk was 0.81, with a 95% confidence interval of 0.74-0.89. The studies varied, and the authors noted possible publication bias.
Those findings do not prove that any particular yogurt prevents colds or flu.
What yogurt can offer, and what the label shows
Yogurt with live cultures may affect the gut microbiome. But findings from probiotic research do not automatically apply to every product. Studies test particular strains, amounts, and schedules. The words "live cultures" alone do not show that a yogurt contains the same strains or amounts used in a trial. Treat claims such as "gut health" or "immune support" as marketing statements to assess, not proof of a health benefit.
Protein is easier to check. Greek yogurt and skyr often contain more protein per serving than some other yogurts, though the amount depends on the product and serving size. Compare protein grams with calories to assess protein density. Check added sugars, too, rather than trusting front-of-pack language. This guide to protein-rich snacks offers another way to compare everyday options.
Claims Check: A Cochrane review found a possible reduction in acute upper respiratory infections with probiotics, but the evidence was low certainty. The findings do not establish that yogurt prevents flu, and they cannot be assumed to apply to every product labeled with live cultures.
The Nutrition Facts panel is more useful for comparing nutrients than for judging probiotic effects. Check the serving size, protein, calories, and added sugars. The FDA's Nutrition Facts label guide explains how to read those values.
If a package makes a specific probiotic claim but does not name the strain or give an amount, that is a transparency gap. It does not prove the product is ineffective, but it is a reason not to assume it contains a dose tested in research.
Make it a regular food, not a cold remedy
Dietitians recommend yogurt as a practical option if it suits your preferences and dietary needs. Add berries or other fruit, nuts, or seeds. You can also use plain yogurt in a savory bowl with cucumber, tomato, red onion, and chickpeas. Fruit adds fiber. Ginger, turmeric, and cinnamon can add flavor, but none is a proven infection remedy.
When comparing yogurt with a nutrition shake or protein powder, check the same details: serving size, protein, calories, added sugars, and ingredient disclosures. Yogurt is a food, so its nutrition information appears on a Nutrition Facts panel, not a supplement-style Supplement Facts panel. A longer ingredient list or a "clean" or "immune-supporting" claim does not show, by itself, that a product has a meaningful clinical effect.
Yogurt can be part of a varied diet, alongside habits such as getting enough sleep and washing your hands. The NIH healthy-living guidance notes that no single food replaces established prevention measures, including recommended vaccination.
Choose yogurt for its nutrients and taste, and use the label to compare products. Probiotics and fermented dairy may affect some immune measures and could change the risk of certain respiratory infections. But the evidence does not support treating yogurt as immunity insurance or as a way to prevent or treat a cold, flu, or other illness.
