Effects of citrus juice fermented with Lactobacillus plantarum YIT 0132 on Japanese cedar pollinosis during probiotic consumption: an open study

Certain strains of lactic acid bacteria (LAB) have beneficial effects on Japanese cedar pollinosis (JCPsis), which is a major concern in Japan. Heat-killed Lactobacillus plantarum YIT 0132 (LP0132), selected for its ability to induce interleukin (IL)-10, has been shown to suppress JCPsis symptoms. Lactobacillus casei Shirota (LcS), a popular probiotic, potentially induces a high level of IL-12 and is reported to delay the onset of JCPsis symptoms. However, it is unclear whether a combination of different types of LAB exerts additional effects without interfering with the benefits of each individual LAB. Thus, we conducted a pilot study to investigate the effects of LP0132-fermented citrus juice on JCPsis during simultaneous consumption of LcS-fermented milk. Fifty-nine subjects with JCPsis were allocated to two groups after a 2-week preconsumption period: one group consumed LP0132-fermented citrus juice and LcS-fermented milk (LcS+LP0132 group) for 12 weeks, while the other consumed LcS-fermented milk alone (LcS group). JCPsis symptoms, JCPsis-associated quality of life (QOL) impairment, and bowel movements were assessed by questionnaires. Compared with the LcS group, the LcS+LP0132 group showed significant alleviation of total symptoms and total ocular symptoms during the consumption period, as well as relief of impaired QOL. Bowel movements were significantly improved during the consumption period compared with the baseline in a combined analysis of all subjects in the two groups. In conclusion, LP0132-fermented citrus juice appears to have positive effects on some JCPsis symptoms and QOL in a population consuming immunomodulating probiotics such as LcS-fermented milk.