Cyanobacterial Harmful Algal Bloom Toxin Microcystin and Increased Vibrio Occurrence as Climate-Change-Induced Biological Co-Stressors: Exposure and Disease Outcomes via Their Interaction with Gut–Liver–Brain Axis

Abstract

The effects of global warming are not limited to rising global temperatures and have set in motion a complex chain of events contributing to climate change. A consequence of global warming and the resultant climate change is the rise in cyanobacterial harmful algal blooms (cyano-HABs) across the world, which pose a threat to public health, aquatic biodiversity, and the livelihood of communities that depend on these water systems, such as farmers and fishers. An increase in cyano-HABs and their intensity is associated with an increase in the leakage of cyanotoxins. Microcystins (MCs) are hepatotoxins produced by some cyanobacterial species, and their organ toxicology has been extensively studied. Recent mouse studies suggest that MCs can induce gut resistome changes. Opportunistic pathogens such as Vibrios are abundantly found in the same habitat as phytoplankton, such as cyanobacteria. Further, MCs can complicate human disorders such as heat stress, cardiovascular diseases, type II diabetes, and non-alcoholic fatty liver disease. Firstly, this review describes how climate change mediates the rise in cyanobacterial harmful algal blooms in freshwater, causing increased levels of MCs. In the later sections, we aim to untangle the ways in which MCs can impact various public health concerns, either solely or in combination with other factors resulting from climate change. In conclusion, this review helps researchers understand the multiple challenges brought forth by a changing climate and the complex relationships between microcystin, Vibrios, and various environmental factors and their effect on human health and disease.

Periodic heat waves-induced neuronal etiology in the elderly is mediated by gut-liver-brain axis: a transcriptome profiling approach

“…It plays a role in various disease conditions involving endocrine, humoral, metabolic, and immune pathways 69 . The impact of climate change on neurological diseases and gastrointestinal health, including the liver-brain axis, has been highlighted, with potential implications for metabolic liver diseases and associated neuropathologies 70 . The increased activity in chemokine signaling, Th1 and Th2 signaling, neuroinflammation signaling, synaptic long-term depression signaling, adipokine signaling, etc.…”

Evaluation of cyanotoxin L-BMAA effect on α-synuclein and TDP43 proteinopathy

“…The cyanobacteria-gut-brain axis represents an intriguing and relatively unexplored connection between the microbial world and the intricate communication network within the human body. While the specific mechanisms of interaction remain a subject of ongoing investigation ( 77 ), it is hypothesized that cyanobacteria may produce many different compounds or metabolites that can modulate neuronal activity. Understanding the cyanobacteria-gut-brain axis at the neuronal level opens new scenarios for research and unravelling the intricacies of this relationship may provide insights into the development of innovative therapies targeting the gut microbiome to positively influence brain function.…”

Algae in Recreational Waters: An Overview within a One Health Perspective

“…In fact, a recent study showed that increased pathogenic Vibrio sp. occurs when algal toxins increase [72].…”