Featured Articles

In humans, changes in the gut-microbiome can have a significant impact on peripheral immune responses. Gut-microbiota imbalances are associated with health conditions such as irritable bowel syndrome, type 2 diabetes and eczema. There is emerging research suggesting that tryptophan metabolism may be linked to gut-microbiota interactions that maintain healthy immune responses in humans. Correspondingly, plants have evolved to possess a complex innate immune system characterized by “multikingdom microbial communities”. Plant roots are colonized by a diverse range of symbiotic microbes such as bacteria and fungi and together, they maintain host-microbe homeostasis and plant health. However, this can be compromised under... read more

Anxiety disorders affect around 4% of the world’s population and is one of the most common mental illnesses. Recent studies have shown that the gut-brain axis plays an integral part in psychiatric health. In fecal transplant models, mice exhibit anxiety-like behaviors when receiving fecal microbiota from depressed individuals. This highlights the contribution that microbes play in human diseases. A recent study published by Dr. Christopher R Brydges et al. in Scientific Reports investigated how microbe tryptophan metabolism affects depression and anxiety levels. Indole levels are significantly associated with age, height, and weight (indole-3-lactic acid (ILA) and the ILA/Indoxyl sulfate (IS)... read more

In 2017, alcohol use accounted for 2.84 million deaths, and it is estimated that nearly 1.5% of the population has alcohol use disorder (AUD) worldwide. Risk factors include binge drinking, adolescent alcohol use, family history of AUD, and psychiatric conditions including PTSD and ADHD. Treatment typically includes detoxification, counseling, and medical intervention.  AUD is associated with significant changes in the gut microbiota which could alter the overall metabolic profile and impact the brain via the gut-brain axis. A recent study published by Dr. Sophie Leclercq et al. in Translational Psychiatry investigated alterations in the levels of kynurenine pathway metabolites and... read more

Nearly 500 million people worldwide have diabetes and around 90% of all cases are type 2 diabetes (T2D). Physical inactivity, obesity, and poor diet are risk factors for T2D. Interestingly, obesity and insulin resistance has been associated with the kynurenine pathway. Suggesting downstream metabolites may play a role in T2D. It is becoming increasing clear that changes in the microbiome can contribute to many diseases. In mice lacking IDO, microbial breakdown of tryptophan is observed, likely due to the increased availability of tryptophan. Therefore, the competition between host and microbiota for tryptophan might underpin the risk for diseases via shifts... read more

Kidney failure effects two million people worldwide. Currently, the best treatment option is transplantation however there is a severe shortage of donated kidneys. Of individuals who receive a kidney, around 4% reject the new organ. Failed transplantation is the result of tubular epithelial cell (TEC) injury by the host immune system. Over 20 years ago, the role of IDO was made known to the world when Dr. David Munn and colleagues showed that allogenic rejection is prevented by indoleamine 2, 3-dioxygenase (IDO), published in Science (Munn et al. 1998). Now there is more evidence that downstream catabolites of TRP play... read more

Epithelial ovarian cancer is the most common type of ovarian cancer and has a high degree of mortality. Chemotherapy in conjunction with surgery is used to treat ovarian cancers however, there has been a high degree of chemotherapy-resistant tumors leading to a decreased survival rating. Therefore, understanding and overcoming immune tolerance within the tumor microenvironment (TME) is critical for the success of future therapeutics. A recent study published by Dr. Adaobi Amobi-McCloud et al. in Frontiers in Immunology investigated indoleamine 2,3-dioxygenase (IDO-1) and the kynurenine (KYN) pathway as a potential immunosuppressive target. The study showed that ovarian cancer patients with... read more

Multiple sclerosis (MS) is a chronic autoimmune disease leading to the demyelination of nerve cells in the central nervous system. Nearly 3 million people worldwide suffer from this debilitating disease. Although there is no cure for MS, recent studies have shown that exercise regimens have a positive effect on both motor and cognitive function in people with MS. The recent study published by Niklas Joisten et al. in Neurology Neuroimmunology & Neuroinflammation is a secondary analysis (Joisten et al, 2019) that assessed how aerobic exercise influences plasma levels of kynurenine pathway (KP) metabolites, neurofilament light chain (pNfL), and interleukin 6... read more

Peripartum depression (PPD) is a mood disorder with symptom onset during pregnancy and up to four weeks after childbirth and is reported in 15-20% of pregnant women worldwide.  Depressive symptoms can range from mild mood changes to severe depression with suicidal behaviors. After delivery the most common cause of death in mothers is suicide, highlighting the severity of PPD. The recent study published by Qiong Sha et al. in the Journal of Affective Disorders expands on previous research that looked at inflammation and kynurenine pathway dysregulation in women with PPD that experienced severe and suicidal depression. In the most recent... read more