Mouth Microbes transmitted to gut Could Help Diagnose gastrointestinal Cancers

Amazing stuff! Cancer is history (soon)!

Is this maybe another good reason to do daily tongue scraping?

"... In a new study, researchers have shown that mouth bacteria migrate through the gastrointestinal tract in certain types of cancer.1 The findings raise hope that the breakdown of these carefully sectioned-off compartments in the body could be an indicator of disease, leading to easier and quicker diagnostic tests for gastrointestinal cancers. ..."

"... In a study ... researchers report that by analyzing the make-up of oral microbes, they may be able to detect signals associated with gastric (stomach) and colorectal cancer. These findings could lead to the development of new, less-invasive screening tests for gastrointestinal cancers. ...

To conduct the study, the researchers recruited 507 volunteers to donate both oral and fecal samples, using a highly standardized collection process. The cohort included 129 healthy individuals; 215 people with metabolic disorders such as metabolic syndrome, hypertension, hyperlipidemia, and type 2 diabetes; 77 people with gastric cancer; and 86 people with colorectal cancer. For the volunteers with cancer, samples were collected before the start of any treatment.  ...

The findings were more nuanced than a simple cancer-versus-healthy comparison. The MF index was significantly elevated in patients with gastric or colorectal cancer but not in people with metabolic disorders. After accounting for alcohol consumption, regular exercise, and BMI, the association remained robust for both gastric and colorectal cancers. ..."

From the highlights and abstract:

"Highlights

• Mouth and gut microbial compartmentalization is disrupted in gastrointestinal cancers

• Mouth-to-gut transmitted bacteria correlate with metabolic and inflammatory markers

• Oral-fecal transmission signatures enable cancer classification by oral microbiome alone

• Transmission-based classifier surpasses microbiota models and fecal occult blood testing

Summary

The human microbiome is spatially compartmentalized, yet oral bacteria can ectopically colonize distal sites such as the gut, potentially influencing disease.

By analyzing paired oral and fecal microbiomes from 507 participants across healthy controls and patients with metabolic disorders or gastrointestinal cancers, we established a quantitative mouth-to-feces (MF) index to measure MF microbial transmission.

The MF index revealed elevated mouth-to-gut transmission in cancer and a strong association with host metabolic and inflammatory indicators.

Using transmitted taxa, we developed a random forest classifier that accurately distinguished gastric/colorectal cancer from healthy controls across seven independent cohorts, even when trained solely on oral microbiome data.

When benchmarked against the conventional screening test, the MF-based model achieved markedly higher sensitivity than the fecal occult blood test.

These findings uncover disease-specific transmission signatures and highlight MF microbial profiling as a generalizable, non-invasive framework for gastrointestinal cancer diagnosis and risk stratification."

Mouth Microbes Could Help Diagnose Gastric Cancers | The Scientist "Some mouth bacteria migrate to the gut in gastrointestinal cancers, opening possibilities for more convenient cancer diagnostic tests."

Mouth and gut microbes could help detect gastrointestinal cancers

Mouth-to-gut microbial transmission signatures enable robust, non-invasive diagnosis of gastrointestinal cancers (open access)

Graphical abstract

Figure 2. MF transmission index as an assessment of the mouth-gut microbiome axis

How your genes influence the microbes and cavities in our mouth

Amazing stuff!

"Highlights

• A new study suggests that our genetics plays a role in determining the microbial community living in our mouths.
• Scientists discovered 11 regions of the human genome that influence the abundances of dozens of bacterial species in the mouth.
• The authors found a relationship between a human gene and oral bacteria that plays a role in dental health.

...

found a surprisingly large effect of human genetics on the abundance of microbes in the mouth. The researchers discovered genome-to-genome interactions between human DNA and the DNA of the oral microbiome. For example, they found that a human gene, AMY1, was strongly linked to the composition of the oral microbial community, and even to dentures use, suggesting that the relationship between this gene and the bacteria in the mouth plays a role in oral health. ..."

From the abstract:

"Human genetic variation influences all aspects of our biology, including the oral cavity, through which nutrients and microbes enter the body. Yet it is largely unknown which human genetic variants shape a person’s oral microbiome and potentially promote its dysbiosis.

We characterized the oral microbiomes of 12,519 people by re-analysing whole-genome sequencing reads from previously sequenced saliva-derived DNA. Human genetic variation at 11 loci (10 new) associated with variation in oral microbiome composition.

Several of these related to carbohydrate availability; the strongest association (P = 3.0 × 10−188) involved the common FUT2 W154X loss-of-function variant, which associated with the abundances of 58 bacterial species.

Human host genetics also seemed to powerfully shape genetic variation in oral bacterial species: these 11 host genetic variants also associated with variation of gene dosages in 68 regions of bacterial genomes. Common, multi-allelic copy number variation of AMY1, which encodes salivary amylase, associated with oral microbiome composition (P = 1.5 × 10−53) and with dentures use in UK Biobank (P = 5.9 × 10−35, n = 418,039) but not with body mass index (P = 0.85), suggesting that salivary amylase abundance impacts health by influencing the oral microbiome.

Two other microbiome composition-associated loci, FUT2 and PITX1, also significantly associated with dentures risk, collectively nominating numerous host–microbial interactions that contribute to tooth decay."

How genes influence the microbes in our mouths | Broad Institute "Analysis of the now largest collection of oral microbiome profiles reveals interactions between human and bacterial DNA. "

Human and bacterial genetic variation shape oral microbiomes and health (open access)

Fig. 1: Oral microbiomes in 12,519 individuals measured by WGS [whole-genome sequencing] of saliva samples.

Human oral Microbiome Evolution with Christina Warinner

Very recommendable! Excellent talk! Fascinating research!

Some newly discovered bacteria of the human mouth/teeth vanished suddenly about 200 years ago after having been with humans for about 40,000 years or so.