Whilst some of the observed evidence suggests significant potential of the strain to benefit a range of neurological conditions, such as Parkinson’s disease (PD) and Alzheimer’s disease (AD), conflicting evidence arising from the significant influence of confounders within these specific groups is noted.
“Further studies are needed to address the precise role of this bacterial species in these topics, specifically in analysing the administration of live, pasteurized, and single components of A. muciniphila in order to make the most of its promising features,” the Italian researchers conclude, highlighting the general lack of strong human data into this area.
They emphasise the potential for the strain and add that further research will provide a more accurate insight into the specific mechanisms of action to “better elucidate its properties in several major areas, paving the way for a more integrated and personalized therapeutic approach”.
Bacterial benefits
The reported benefits associated with a healthy microbiome are vast, with research booming into various bacterial strains over recent years.
One such strain, identified as Akkermansia muciniphila in 2004 following its observed growth on a mucin substrate, is thought to make up 1-3% of the total microbiota in healthy individuals. It has been observed that the species is able to degrade and utilise the mucin to produce beneficial short-chain fatty acids (SFCA), whilst enhancing intestinal barrier function and reducing gut permeability to adverse microbes.
Following these benefits, as well as its established heat stability and positive European Food Safety Authority (EFSA) assessment, there has been a heightened interest in the study of Akkermansia. It has been noted that intestinal dysbiosis has been characterised by depleted populations of the bacteria, subsequently being linked to inflammatory and metabolic conditions such as obesity and bowel diseases.
The researchers conducted the present review to collate the available evidence regarding the effects of Akkermansia, to conclude on its efficacy within therapeutic probiotics.
Akkermansia action
The researchers note the negative correlation between A. muciniphila and body weight that has been observed in both human and animal models, with studies highlighting associated increases in secretion of glucagon-like peptide-1 (GLP-1). The hormone has been shown to increase insulin secretion, ultimately reducing postprandial glucose spikes. Thus, the species has been noted to be associated with a reduced risk of metabolic syndrome and T2D, yet the number of human trials are low in this area.
Furthermore, the review spotlights the strain’s potential to influence neurological diseases, following the knowledge that colonic inflammation and increased gut permeability have been associated with conditions such as PD and AD. Specifically, the researchers also note studies suggesting an increased abundance of A. muciniphila in the faecal samples of those with PD, hypothesising that the resultant increased gut permeability may enhance absorption of bacterial toxins.
However, the opposite was observed in studies of mouse models of AD, highlighting the inconclusive nature of the data in this area paired with a lack of human trials.
For the future
The researchers highlight the significance of the collated evidence demonstrating the potential of Akkermansia across a range of conditions, explaining its action: “The production of small metabolites and mediators, the influence on microbial diversity and the preservation of the gut barrier integrity promoted by A. muciniphila have been proven to exert a beneficial effect not only on the gut but also on a series of diseases involving the metabolic, cardiovascular, neurological, and even oncological fields.”
With regards to the general lack of strong data utilising human RCTs, they add: “Further studies are needed to provide more accurate insight into its mechanisms of action and to better elucidate its properties in several major areas, paving the way for a more integrated and personalized therapeutic approach that finally makes the most of our knowledge of the gut microbiota.”
Source: Nutrients
https://doi.org/10.3390/nu15081815
“Role of Akkermansia in Human Diseases: From Causation to Therapeutic Properties”
by Antonio Pellegrino, Gaetano Coppola, Francesco Santopaolo, Antonio Gasbarrini and Francesca Romana Ponzia