A 10-patient case study on the influence of two different probiotics on individual intestinal microbiota.

BACKGROUND Probiotics increase beneficial microbiota and improve chronic conditions, such as atopic diseases, irritable bowel disease, and obesity. However, because there are so many probiotics, it is unknown which probiotics might have more of an effect on intestinal microbiota. OBJECTIVE To understand how two different types of probiotics influence human intestinal microbiota, human fecal microbiota were analyzed after ingestion of each of the probiotics. MATERIALS AND METHODS Ten outpatients were enrolled. Study A: Five patients took Lactobacillus buchneri (SU) for 4 weeks and mixed probiotics (NS) for the following 4 weeks. Study B: One year after study A, the other five patients took NS for 4 weeks at first and SU for the following 4 weeks. Fecal samples were collected before and after the outpatients took each of the two probiotics and were then analyzed. RESULTS Study A: Three of the five patients had a decreased percentage of beneficial bacteria (Lactobacillales, Bifidobacteria species) after taking SU (change [expressed as mean±standard deviation] from 13.7%±7.1% to 4.0%±3.5%), whereas the remaining two patients showed an increased percentage (from 16.8%±3.4% to 30.4%±4.6%). After taking NS, the three patients who had a decreased percentage of beneficial bacteria after taking SU increased (from 4.0%±3.5% to 8.0%±2.1%), whereas the two patients who had increased beneficial bacteria after taking SU showed a decreased percentage (from 30.4%±4.6% to 16.4%±7.4%). Study B: All five patients had increased beneficial bacteria after taking NS (from 9.9%±2.9% to 14.5%±4.8%). After taking SU, all five patients had decreased bacteria (14.5%±4.8% to 10.9%±5.8%). CONCLUSION The two probiotics studied had different influences. Probiotics should be selected not only for their quality but also for compatibility with each intestinal bacterial flora.