Introducing another reducer of the Bifidobacterium (and other bacteria): Gut parasites like Blastocystis
So far, the previous Substacks include studies showing reduced levels of Bifidobacterium in those who drink, smoke, and have taken specific antibiotics.
There are several parasites that exist in variable amounts in the “guts” of people.
Of these parasites, a number impact the gut microbiome.
These are just a few:
Giardia lamblia, also known as Giardia intestinalis or Giardia duodenalis, is a common intestinal parasite that causes giardiasis.
Chronic giardiasis has been associated with alterations in the gut microbiota, including reductions in bifidobacteria populations.
Entamoeba histolytica is the causative agent of amoebiasis, a parasitic infection of the intestines.
Studies have suggested that Entamoeba histolytica infection can lead to dysbiosis in the gut microbiota, affecting the abundance of bifidobacteria among other beneficial bacteria.
Blastocystis is a single-celled parasite found in the human intestine. While its pathogenicity is debated, some studies have suggested that Blastocystis infection can change bifidobacteria levels.
We’re going to focus on Blastocystis.
There are several mechanisms by which parasites like blasto are theorized cause a lowering of good bacteria in our guts, like Bifidobacteria:
Blastocystis and bifidobacteria may compete for resources within the gut environment. Both rely on nutrients present in the intestinal tract, and an overgrowth of Blastocystis might potentially outcompete bifidobacteria for these resources, impacting their growth and survival.
Blastocystis infection can lead to changes in the gut environment, such as alterations in pH, creating a less conducive to the growth and survival of bifidobacteria, thereby affecting their population (like smoking does).
The immune response triggered by Blastocystis infection could indirectly impact bifidobacteria. due to immune-mediated changes in the gut environment might influence the growth and composition of bifidobacteria.
Several studies show higher levels of Blastocystis correlate to lowered levels of our good bacteria, like lowering of Bifidobacteria.
Interactions between a pathogenic Blastocystis subtype and gut microbiota: in vitro and in vivo studies
”Generally, Blastocystis ST7 exerts a positive effect on the viability of representative gut bacteria except on Bifidobacterium longum. Gene expression analysis and flow cytometry indicate that the bacterium may be undergoing oxidative stress in the presence of Blastocystis. In vitro assays demonstrate that Blastocystis-induced host responses are able to decrease Bifidobacterium counts. Mice infected with Blastocystis also reveal a decrease in beneficial bacteria Bifidobacterium and Lactobacillus.”
That is not the only study showing lowered levels of Bifidobacteria in connection to rises in parasites such as Blasto.
”A meta-analysis of 13 publications confirmed the lower abundance of Bifidobacterium in IBS patients, along with decreased Lactobacillus and F. prausnitzii [122]. In other studies, the proportion of Bifidobacterium in intestinal microbiota decreased in Blastocystis-positive individuals with IBS, while a decrease in F.”
Let’s keep going.
”Recent studies reported Blastocystis infection decreases the proportion of beneficial bacterial, such as Bifidobacterium and Lactobacillus”
“Gut microbiota modifications reported from IBS subjects primarily associated an increase of Enterobacteriaceae with a decrease of both Lactobacilli and Bifidobacteria”
”Our data indicated that men with IBS-C had a significant decrease in Bifidobacterium sp. when infected by Blastocystis. Interestingly, in control subjects (i.e. without any gastrointestinal disorder) positive for Blastocystis, Faecalibacterium prausnitzii, which is known for its anti-inflammatory properties, was significantly decreased in men”
Yikes on bikes:
Presence of Blastocystis in gut microbiota is associated with cognitive traits and decreased executive function
”Scatter plots of the partial Spearman’s rank correlations (adjusted for age, BMI, sex and education years) between the baseline faecal centered log-ratio (clr) transformed Blastocystis subtypes values and executive function assessed by the total digit span test (TDS), the trail making test part-B (TMTB) and the Stroop interference (STROOPI) in the discovery cohort (IRONMET, n = 114) at baseline. The ranked residuals are plotted. g Boxplots of alpha diversity indices according to the tertiles of the clr-transformed Blastocystis subtype 1 (ST1), h subtype 2 (ST2), i subtype 3 (ST3), and j subtype 4 (ST4). Global differences were assessed using a Kruskal-Wallis test and pairwise comparisons were assessed using a Wilcoxon rank sum tests with Bonferroni multiple testing correction. k Principal component analysis scores plot of the clr-transformed microbial data coloured according to the clr-transformed ST1 tertiles, l ST2 tertiles, m ST3 tertiles, and n ST4 tertiles. Overall differences in the microbiome composition were assessed by PERMANOVA using 1000 permutations and Euclidean distances. Pairwise differences between groups were assessed using the pairwise.adonis function adjusted for Bonferroni correction. #p < 0.1; *p < 0.05; **p < 0.01, ***p < 0.001. o–r Scatter plots of the partial Spearman’s rank correlations (adjusted for age, BMI, sex and education years) between the baseline faecal centered log-ratio (clr) transformed Blastocystis subtypes values and executive function assessed by the TDS and the STROOPI in the discovery cohort after 1-year of follow-up (IRONMET, n = 75).”
“Blastocystis subtypes are associated with bacterial composition in a longitudinal discovery cohort.”
”Blastocystis subtypes are linked to bacterial functionality related to aromatic amino acid metabolism and folate-mediated pyrimidine and one-carbon metabolism.”
These are some complicated graphs, absolutely.
”Blastocystis subtypes are associated with executive function in three independent validation cohorts.”
”Blastocystis are associated with bacterial composition and functionality in a large validation cohort.”
Oh boy
“Human donor cognitive traits seem to be transmitted to recipient mice in parallel to changes in the expression of mPFC gene involved in memory formation and pyrimidine metabolism.”
What this means:
Association with Cognitive Deficits: Blastocystis subtypes present in the gut microbiota were associated with deficits in executive function across different cohorts. Specifically, Blastocystis subtype 1 levels were linked to impaired executive functioning in subjects both above and below 60 years of age, while subtypes ST2, ST3, and ST4 showed associations mainly in subjects below 60 years.
Relationship with Gut Microbiome Diversity: Blastocystis presence was associated with alterations in gut microbiome diversity, with different subtypes showing varying effects. Higher levels of ST1 were correlated with increased alpha diversity, while ST2 and ST3 were associated with lower alpha diversity. Additionally, both high and low levels of ST4 were linked to higher alpha diversity compared to middle levels.
Blastocystis presence was strongly associated with shifts in microbial composition and functionality.
Notably, Blastocystis subtypes were negatively associated with beneficial bacteria such as Bifidobacterium and Lactobacillus, which have been linked to cognitive function improvement in previous studies, meaning the blasto was linked to lowered amounts of bifido and lacto.
Blastocystis subtypes were linked to bacterial functions related to pyrimidine, one-carbon, and aromatic amino acid metabolism, which are critical for cognitive function.
These shifts in bacterial functionality were reflected in the circulating metabolome.
Microbiota transplantation experiments in mice showed that recipient mice exhibited altered cognitive function and gene expression in the prefrontal cortex when transplanted with gut microbiota from donors carrying Blastocystis subtypes.
The study also explored potential mechanisms underlying the relationship between Blastocystis and cognition, including increased intestinal permeability, mucosal sloughing, goblet cell mucin increase, and induction of pro-inflammatory cytokine response, which may contribute to cognitive dysfunction.
Regarding the blasto versus bifido component, the existence and persistence of blasto meant lowered levels of bifidobacteria.
I wonder what this means for people who contracted Covid?