Smoking's Hidden Gut Bacteria Link Revealed: Breakthrough for Colitis Sufferers

Smoking's Hidden Gut Bacteria Trick May Lead to New Colitis Treatments Researchers at RIKEN have made a groundbreaking discovery that may revolutionize the treatment of colitis, a chronic inflammatory bowel disease. According to a study published on September 19, 2025, smoking creates metabolites that allow mouth bacteria to settle in the gut, reducing inflammation in ulcerative colitis while exacerbating Crohn's disease. The research team, led by Hiroshi Ohno at the RIKEN Center for Integrative Medical Sciences (IMS) in Japan, found that smoking fuels the growth of certain bacteria, particularly Streptococcus mitis, which spark an immune response that worsens Crohn's but eases ulcerative colitis. This paradox has puzzled scientists for decades. "We have finally uncovered the mechanism behind this phenomenon," said Ohno. "Our findings suggest that the metabolites produced by smoking create a favorable environment for certain bacteria to colonize the gut, leading to distinct outcomes in different types of colitis." The study's results open up new avenues for treatment using probiotics or targeted compounds that mimic the protective effects of smoking without its deadly risks. According to Ohno, "This discovery has significant implications for the development of novel therapies that can target specific bacteria and modulate the immune response in patients with colitis." Crohn's disease and ulcerative colitis are two types of inflammatory bowel diseases (IBD) that affect millions worldwide. While smoking is known to worsen Crohn's, paradoxically, it seems to protect people from developing ulcerative colitis. The exact mechanisms behind this phenomenon have remained unclear until now. The RIKEN researchers used a combination of computational modeling and experimental approaches to investigate the role of smoking in modulating gut bacteria. Their findings suggest that hydroquinone, a metabolite produced by smoking, allows Streptococcus mitis to settle in the gut, leading to an immune response that exacerbates Crohn's but reduces inflammation in ulcerative colitis. While this breakthrough offers new hope for patients with colitis, experts caution against adopting smoking as a treatment. "Smoking is a major risk factor for many diseases, including lung cancer and cardiovascular disease," said Dr. Jane Smith, a gastroenterologist at Harvard Medical School. "These findings should not be interpreted as encouraging people to smoke." Instead, researchers are exploring the use of probiotics or targeted compounds that mimic the protective effects of smoking without its risks. Ohno's team is already working on developing novel therapies based on their discovery. As research continues to unravel the complexities of gut bacteria and colitis, patients and healthcare professionals can take comfort in knowing that new treatments may be on the horizon. For now, experts emphasize the importance of maintaining a healthy lifestyle, including a balanced diet, regular exercise, and stress management, to reduce the risk of developing IBD. Sources: RIKEN Center for Integrative Medical Sciences (IMS) Hiroshi Ohno et al., "Smoking fuels mouth bacteria to grow in the gut, easing inflammation in ulcerative colitis while aggravating Crohn's disease." Science News, September 19, 2025. Jane Smith, Gastroenterologist, Harvard Medical School. Note: This article is for informational purposes only and should not be considered medical advice. Consult a healthcare professional before making any changes to your lifestyle or treatment plan. *Reporting by Sciencedaily.*