Monthly Archives: August 2024

Evidence that the gut microbiome has an impact on height pre skeletal maturity

There is evidence that the gut microbiome influences height via IGF-1. Microbiomes are passed on from mothers to children so it is non genetic way to influence height. Here’s more information about how the guy microbiome influences height.

The gut microbiome is definitely something that has a lot of effort put into it by the scientific community so there is potential to optimize the gut microbiome to make people taller.

Island biogeography theory provides a plausible explanation for why larger vertebrates and taller humans have more diverse gut microbiome

“Prior work has shown a positive scaling relationship between vertebrate body size, human height, and gut microbiome alpha diversity.{this means that the more diverse your gut microbiome the taller you were. This could be a correlation rather than causal if there is a factor that increases human height and gut microbiome diversity}.
This observation mirrors commonly observed species area relationships (SARs) in many other ecosystems. Here, we expand these observations to several large datasets, showing that this size–diversity scaling relationship is independent of relevant covariates, like diet, body mass index, age, sex, bowel movement frequency, antibiotic usage, and cardiometabolic health markers. Island biogeography theory (IBT), which predicts that larger islands tend to harbor greater species diversity through neutral demographic processes, provides a simple mechanism for positive SARs. Using a gut-adapted IBT model, we demonstrated that increasing the length of a flow through ecosystem led to increased species diversity, closely matching our empirical observations. We delve into the possible clinical implications of these SARs in the American Gut cohort. Consistent with prior observations that lower alpha diversity is a risk factor for Clostridioides difficile infection (CDI), we found that individuals who reported a history of CDI were shorter than those who did not and that this relationship was mediated by alpha diversity.{so increased microbiome diversity reduces the risk of infection}.

We observed that vegetable consumption had a much stronger association with CDI history, which was also partially mediated by alpha diversity. In summary, we find that the positive scaling observed between body size and gut alpha diversity can be plausibly explained by a gut-adapted IBT model, may be related to CDI risk, and vegetable intake appears to independently mitigate this risk, although additional work is needed to validate the potential disease risk implications.”

So this indicates that vegetable intake is a good way to increase microbiome diversity.

“The human gut microbiota has an enormous impact on our phenotype, with almost half of the metabolites circulating in blood significantly associated with cross-sectional variation in the ecological composition of the gut microbiome. One of the key ecosystem functions that the gut microbiota provides to its host is resistance to enteric bacterial pathogens. Niche saturation or nutrient competition are commonly invoked mechanisms for how the microbiota excludes invaders.”

“species-diverse commensal communities are more apt to saturate available metabolic niches
so that an invasive pathogen is less likely to colonize, outcompete commensals, and cause disease”<- so one of the ways that the gut microbiome increases height is by competing with invading pathogens and thereby preventing them from stunting growth. However if it is due to preventing infection that height is increased it could mean that for the average person the microbiome has less impact on height if they would not get an infection otherwise. On the other hand, the microbiome has been shown to have other effects that influence height such as via IGF-1.

“Vertebrate body size, which varies over six orders of magnitude, has been shown to be positively associated with gut microbiome alpha diversity, indicating that larger animals with larger guts harbor more species.” <-so the correlation could be possibly caused by larger people having larger guts which enable more microbiome diversity.

“we demonstrate a consistent scaling between body size and gut microbiome alpha diversity across vertebrates and human populations. We find that this association is independent of many potential confounders, like diet, bowel movement frequency (BMF), body mass index (BMI), age, and sex”

What the next steps would be to test the influence of the microbiome would be to compare the growth rates of different animals versus microbiome diversity who have never had an infection.

But with the frequency that kids get sick even if microbiome only reduces infection risk then it is worth it.

Paper suggests that stimulating PTHrp directly may be a way to boost growth plate based longitudinal bone growth

This paper has interesting insights on how mechanical loading and gravity can enhance longitudinal bone growth.

Intermittent mechanical loading on mouse tibia accelerates longitudinal bone growth by inducing PTHrP expression in the female tibial growth plate

“Our goal was to study the role of mechanical loading (one of the components of ambulation) on endochondral ossification and longitudinal bone growth. Thus, we applied cyclical, biologically relevant strains for a prolonged time period (4 weeks) to one tibia of juvenile mice, while using the contralateral one as an internal control. By the end of the 4-week loading period, the mean tibial growth of the loaded tibiae was significantly greater than that of the unloaded tibiae. The mean height and the mean area of the loaded tibial growth plates were greater than those of the unloaded tibiae. In addition, in female mice we found a greater expression of PTHrP in the loaded tibial growth plates than in the unloaded ones.”

This suggests that possibly boosting PTHrP directly could induce additional longitudinal bone growth.

“Mechanical forces related to gravitational changes, ambulation, and exercise may contribute to modulate bone growth.”<-this suggests that exercises that invert and every may modulate longitudinal bone growth.

“daily physical activities transmit complex mechanical loads including tension, compression, torsion, and shear to the skeleton”<-there are many ways to load bones that are under explored.

“Seventy-five 4-week old TOPGAL mice were exposed to mechanical loading using a Bose ElectroForce 3220 dynamic loading system. Before each loading session, mice were anesthetized with 3.5% isoflurane. Each loading session included 100 compressive loading cycles of 5 Newton (N) force to the right tibia at the frequency of 2 Hz per cycle”<-the reason that cyclic loading is more effective than static loading is likely related to fluid flow.

“mean tibial growth of the loaded tibiae was significantly greater than that of the unloaded tibiae, in the whole sample of mice “

This is a pretty significant different in length.

“Gravity and physical activity generate mechanical forces on the long bones and on the growth plates that may be involved in the regulation of bone growth.”<-one of the reasons why lateral loads are so effective is that it applies loads in a different mannerism against gravity.

“Of note, the stimulatory effect of mechanical loading on tibial growth persisted in the 4 weeks following the cessation of loading.

In addition, at the end of the 4-week loading period the whole growth plate and the epiphyseal zone heights, as well as the overall area of the loaded tibial growth plates were significantly greater than those of the unloaded growth plates. Such finding suggests a loading-mediated enhanced growth plate chondrocyte formation”

The study mentions that too high load can suppress growth. So maybe lighter weights are better and applying it the right way is more important but that may be for growth plates and not bones. Higher loads may be needed to stimulate growth in adult bones as bones are tougher tissue than catilage.

“similar studies in rodents indicate that elevated loading forces tend to inhibit longitudinal growth, while strains of lower intensity (like ours) tend to stimulate it. “

“After 4 weeks of loading, we found a greater Pthrp gene expression in the growth plate chondrocytes of the female mouse loaded tibiae, while no difference was found in male mice” however male mice also had greater length. So this suggests that mechanical loading also influences length by mechanisms not related to PTHrP.