Another data set from the ominous life-long feeding study of rats fed Roundup herbicide  has been published. The original study caused a biotech industry panic because of the increased tumours observed in the female rats.
This new spin-off was a pilot study carried out towards the end of the experiment. It looked at the digestive tract health in a small number of surviving rats. The results suggest that Roundup, which is sprayed on and accumulated by most GM crops, may cause an unhealthy disturbance of the gut's microbial population, the 'microbiome' (See Note).
As regards size and complexity, the microbiome trumps the human body: it consists of at least as many cells as we do, and comprises a vast array of microbial species and types of which less than 1% have been studied. Science is just beginning to get a handle on which are the health-promoting 'good' bugs in our innards and which are the 'baddies' linked to disease. However, it's also revealing an intricate web of interactions between the composition of bugs in our guts and our health.
Note on the Microbiome
The bugs in your gut don't just sit there eating up your food before you can get hold of it. They have a role in, for example, the digestion of some foods, degrading toxins, educating the early immune- and hormonal-systems, and the control of inflammation; links to liver function, sugar control and obesity are also emerging.
Surprisingly, gut bacteria can not only produce hormones, but can affect and be affected by their host's hormones. This is where the human-microbiome web really becomes appallingly intricate. Hormones interact with each other, often in a gender-specific way, to control body functioning, immunity and mood (anxiety/well-being). They can also act on targets a long way from their source in the body.
Taken together, the hormones, immune-system, inflammation and mood are all factors which can create a cancer-friendly or -unfriendly environment in a gender-specific way. All these factors are affected positively or negatively by the microbiome, and all of them could, therefore, be altered by Roundup (see Note).
Note on what Roundup in the diet could be doing to our microbiome.There are at least three possibilities: one, glyphosate, the active weed-killing component of Roundup is known to be toxic to certain microbes; two, glyphosate could well be broken down by bugs in the gut to its toxic derivative 'AMPA'; and three, the 'surfactant' ingredients added to Roundup to help glyphosate penetrate into weeds could damage the gut's protective mucus lining. Any or all of these could be happening, and none of them are compatible with health.
The findings suggested by this limited data from the life-long rat feeding study are of microbiome disturbances in the females: there was an increase in 'bad' bugs and a decrease in 'good' bugs, and the effects weren't dose-related. Tellingly, this overlaps with other data from the main experiment which showed non-dose-related gender-specific pathologies in several organ systems.
Given the emerging links between an unhealthy microbiome, hormonal status, the immune system and inflammation, plus the increased tumour incidence observed in the Roundup-fed female rats in the life-long experiment, there is a real cause for concern which indicates an expanded study is needed.
The reason for the lack of a dose response (i.e. the microbiome didn't change more with increasing doses of Roundup) can only be speculated. It may be that the microbiome is resilient to change due to its complexity, so that further microbial adjustments as the Roundup exposure rose are buffered. It may be that the microbiome change wasn't caused directly by Roundup, but was triggered by distant functional disturbances, for example in the liver, induced by the herbicide.
Testing of the effects of all pesticide formulations on the human microbiome is urgently needed. Ask for it.
 GM MAIZE IS NOT SAFE TO EAT - October 2012
- Roundup causes changes in gut microbiome of rats, GM Watch 1.01.18
- Veronica L. Lozano, et al., December 2017, Sex-dependent impact of Roundup on the rat gut microbiome, Toxicology Reports 5
- Susan E. Erdman and Thiofios Poutahidis, 2015, Gut bacteria and cancer, Biochimica et Biophysica Acta
- Hadar Neuman, et al., 2015, Microbial endocrinology: the interplay between the microbiota and the endocrine system, FEMS Microbiology Reviews 39