Daily kombucha intake may stabilize mast cells

SAN ANTONIO — Kombucha may play a role in stabilizing mast cells, but it does not act as an antihistamine in treating allergic reactions, according to data presented at the American Academy of Allergy, Asthma & Immunology Annual meeting.

The study followed reports of decreases in allergic reactions among patients who drank kombucha each day, Valerie Le, MD, second-year fellow in the division of allergy and immunology, Washington University School of Medicine, and colleagues wrote.

“We had some anecdotal evidence from separate patients who would come in with food allergy to alpha-gal and tell us that they were really consistent about drinking kombucha. Their reactions to alpha-gal stopped,” Le told Healio.

Typically, kombucha is a black tea that has been fermented with a symbiotic culture of bacteria and yeast, the researchers said, adding that it has been touted for multiple health benefits including potential anti-inflammatory and immunomodulatory properties.

The researchers administered standardized skin prick tests at baseline to three patients (67% female; 100% non-Hispanic Asian) who were sensitized to Dermatophagoides pteronyssinus (DP) dust mites.

Participants also had SPTs after 1 week and after 2 weeks of drinking 8 oz of kombucha each day. Next, the participants stopped drinking kombucha for 2 weeks, with additional SPTs after each week during this washout period.

The researchers measured wheal size at each time point by the two longest perpendicular axes and reported them as a mean diameter. Patients recorded their rhinitis symptoms as well.

Measurements for histamine (mean, 7.8 mm; range, 6.5-9.5) and saline (mean, 0.8 mm; range, 0-1.5) controls remained relatively consistent through the 4-week study period.

However, DP wheal size decreased from a mean diameter of 9 mm (range, 4.5 mm-17.5 mm) to 5 mm (range, 2 mm-10 mm), or by 45%, for all three patients from baseline to 1 week. From week 1 to week 2, however, wheal size did not change (mean, 5 mm-5.5 mm).

During the first washout week, DP wheal size decreased from a mean of 5.5 mm to 4.5 mm but then increased 13% to a mean of 6 mm after the next week. None of the DP wheal sizes returned to baseline for any of the participants.

All three patients also tolerated kombucha well.

“Interestingly, no one’s rhinitis symptoms changed while on or off the kombucha,” Le said. “But despite having a decrease in skin reactivity, all of the patients noticed that their skin pruritis generally did increase for a little bit while on the kombucha.”

The lack of any change in the histamine measurements indicated that kombucha does not act as an antihistamine, the researchers said, but the decrease in the reactivity to the DP mite SPTs does imply that kombucha may help stabilize mast cells.

The mechanics behind this effect remain unknown, Le said, adding that fermented foods, which are very popular right now, are being examined for their impact on many different diseases including asthma and allergic rhinitis.

“Specifically in our realm, looking at the impact on asthma, allergic rhinitis generally, it looks to have good impacts,” she said. “Whether that’s a change in the microbiome, whether that’s a change in Th1 vs. Th2 responses to allergens, we don’t know.”

These effects require verification in a larger study with other allergens, Le continued. The researchers are now conducting a larger study with alpha-gal food allergy patients and patients with dust mite allergies, examining their gut microbiomes, oral immunophenotyping and SPTs as well.

“Our hope is that we’ll figure it out with time,” she said. “We’ll see.”