Abstract
The prevalence of allergic rhinitis (common allergies) has increased in the last fifty years, from less than one percent to more than twenty-six percent of the population. Today, more than one hundred million people in the US suffer seasonal or yearlong allergies. The hygiene hypothesis was proposed 30 years ago as a potential explanation for this phenomenon, and we built on it with the specific oral hygiene hypothesis. Our longitudinal pilot study suggested that oral probiotic deficiency is the cause of allergic rhinitis. This clinical trial served to verify our theory and evaluate the effectiveness of AllerPops for allergy relief. We carried out a phase II, randomized, double-blind, controlled, single-center 21-day study to investigate the efficacy of AllerPops to reduce nasal symptoms in 72 adult volunteers with seasonal/year-long nasal allergies and its impact on oral microbiome using amplicon sequencing of 16S ribosome RNA genes. The volunteers were randomly separated into two equally sized groups: a control group and an investigational group. Both groups were given at least three doses of AllerPops, taken every other day, and asked to answer questions about observed allergy symptoms. Volunteers in the investigational group cleaned their mouths before taking a dose and slowly dissolve the lozenge, while those in the control did not. Through this trial, we show that AllerPops prebiotic supplements are effective in providing sustained allergy relief (P = 0.002) and can modulate oral beneficial bacteria that produce short-chain fatty acids (SCFA), such as Fusobacteria, Butyrivibrio, and Peptostreptococcus. The clinical improvements correlated with changes in the relative abundance of probiotics significantly: Fusobacteria (R = 0.32, P = 0.009), Butyrivibrio (R = 0.25, P = 0.044), and Peptostreptococcus (R = 0.34, P = 0.005). These results point to the root cause of allergic rhinitis: the lack of oral probiotics that produce SCFA to pacify the immune systems. Future study of AllerPops' theory will help society redefine the best oral hygiene practice to protect oral probiotics so that we may prevent allergic and autoimmune diseases and dental/gum infections. The trial was retrospectively registered at clinicaltrials.com, with registration number NCT05956691, on 21/07/2023.