Emiko Aizawa1, Hirokazu Tsuji2, Takashi Asahara2, Takuya Takahashi2, Toshiya Teraishi1, Sumiko Yoshida3, Miho Ota1, Norie Koga1, Kotaro Hattori1, Hiroshi Kunugi4. 1. Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan. 2. Yakult Central Institute, Tokyo, Japan. 3. Department of Psychiatry, National Center of Neurology and Psychiatry Hospital, Tokyo, Japan. 4. Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan. Electronic address: hkunugi@ncnp.go.jp.
Abstract
BACKGROUND: Bifidobacterium and Lactobacillus in the gut have been suggested to have a beneficial effect on stress response and depressive disorder. We examined whether these bacterial counts are reduced in patients with major depressive disorder (MDD) than in healthy controls. METHOD: Bifidobacterium and Lactobacillus counts in fecal samples were estimated in 43 patients and 57 controls using bacterial rRNA-targeted reverse transcription-quantitative polymerase chain reaction RESULTS: The patients had significantly lower Bifidobacterium counts (P=0.012) and tended to have lower Lactobacillus counts (P=0.067) than the controls. Individuals whose bacterial counts below the optimal cut-off point (9.53 and 6.49log10 cells/g for Bifidobacterium and Lactobacillus, respectively) were significantly more common in the patients than in the controls for both bacteria (Bifidobacterium: odds ratio 3.23, 95% confidence interval [CI] 1.38-7.54, P=0.010; Lactobacillus: 2.57, 95% CI 1.14-5.78, P=0.027). Using the same cut-off points, we observed an association between the bacterial counts and Irritable bowel syndrome. Frequency of fermented milk consumption was associated with higher Bifidobacterium counts in the patients. LIMITATIONS: The findings should be interpreted with caution since effects of gender and diet were not fully taken into account in the analysis. CONCLUSION: Our results provide direct evidence, for the first time, that individuals with lower Bifidobacterium and/or Lactobacillus counts are more common in patients with MDD compared to controls. Our findings provide new insight into the pathophysiology of MDD and will enhance future research on the use of pro- and prebiotics in the treatment of MDD.
BACKGROUND: Bifidobacterium and Lactobacillus in the gut have been suggested to have a beneficial effect on stress response and depressive disorder. We examined whether these bacterial counts are reduced in patients with major depressive disorder (MDD) than in healthy controls. METHOD: Bifidobacterium and Lactobacillus counts in fecal samples were estimated in 43 patients and 57 controls using bacterial rRNA-targeted reverse transcription-quantitative polymerase chain reaction RESULTS: The patients had significantly lower Bifidobacterium counts (P=0.012) and tended to have lower Lactobacillus counts (P=0.067) than the controls. Individuals whose bacterial counts below the optimal cut-off point (9.53 and 6.49log10 cells/g for Bifidobacterium and Lactobacillus, respectively) were significantly more common in the patients than in the controls for both bacteria (Bifidobacterium: odds ratio 3.23, 95% confidence interval [CI] 1.38-7.54, P=0.010; Lactobacillus: 2.57, 95% CI 1.14-5.78, P=0.027). Using the same cut-off points, we observed an association between the bacterial counts and Irritable bowel syndrome. Frequency of fermented milk consumption was associated with higher Bifidobacterium counts in the patients. LIMITATIONS: The findings should be interpreted with caution since effects of gender and diet were not fully taken into account in the analysis. CONCLUSION: Our results provide direct evidence, for the first time, that individuals with lower Bifidobacterium and/or Lactobacillus counts are more common in patients with MDD compared to controls. Our findings provide new insight into the pathophysiology of MDD and will enhance future research on the use of pro- and prebiotics in the treatment of MDD.
Authors: Thomaz F S Bastiaanssen; Sofia Cussotto; Marcus J Claesson; Gerard Clarke; Timothy G Dinan; John F Cryan Journal: Harv Rev Psychiatry Date: 2020 Jan/Feb Impact factor: 3.732