Food Allergies

A striking result in peanut allergy treatment

Food allergies happen when the immune system mistakenly reacts to harmless food proteins, and gut bacteria play a genuine role in training this immune tolerance during early life. One of the most striking findings comes from a trial combining a specific probiotic, Lactobacillus rhamnosus GG, with peanut oral immunotherapy, a treatment that gradually exposes children to small, increasing amounts of peanut protein. Among 62 children who received the combination for 18 months, 89.7% achieved desensitisation, compared with just 7.1% on placebo.

Source: Food Allergy and the Microbiome: Current Understandings and Future Directions

A lasting effect, and an honest caveat

Four years after treatment stopped, 67% of the children who'd received the combination were still eating peanut freely, compared with just 4% of the placebo group, suggesting a genuinely durable change rather than a temporary effect. The honest caveat is that this trial didn't include a probiotic-only group, so it can't fully separate how much of the effect came from the probiotic itself versus the oral immunotherapy alone. A larger follow-up trial in 201 children found that adding the same probiotic to peanut immunotherapy didn't improve results over immunotherapy by itself, a genuinely mixed picture worth being upfront about.

Cow's milk allergy shows a similar pattern

Separate trials in infants with cow's milk allergy found that combining a specific probiotic with hypoallergenic formula increased rates of milk tolerance at 12, 24, and 36 months compared with formula alone. As with any probiotic, this only works if the bacteria are properly fed. A strain given during allergy treatment still needs fibre and plant compounds, from the wider diet, to establish itself well enough to genuinely shift immune tolerance, rather than just passing through.

Source: Food allergy and the microbiome: Current understandings and future directions

What this means for you

Food allergies need proper diagnosis by an allergist, and oral immunotherapy, where appropriate, should only be done under medical supervision given the risk of allergic reactions during treatment. Given the genuine trial evidence above, particularly for peanut and cow's milk allergy, it's reasonable to ask an allergist whether a specific probiotic strain alongside prescribed immunotherapy might help, while being realistic that the evidence is still mixed rather than settled. A varied, plant-rich diet during pregnancy and early childhood supports the same gut bacteria this research ties to healthier immune tolerance. That's the same idea behind GutLab, everyday gut health starts with regularly feeding the microbiome a broad range of plant-rich ingredients.