Our caecum is microscopic (see below); herbivores, gargantuan. The human caecum and appendix serve more of an immune function, reservoir for microbiota; the function for digestion is minor. Both our caecums and large intestines can ferment carbs (fiber, resistant) then release the digested products into the blood circulation as volatile organic acids. The small intestines should not... except under illness (SIBO, small intestinal bowel overgrowth). We are not foregut fermenters. These metabolites can be measured (propionate, acetate, butyrate, etc). GDX/Metametrix organic acids testing is available-- Nutri Eval, Organix, ION, ONE. I favor the ONE -- requires only the first morning void urine (FMV) so non-invasive and you get the cancer/inflammatory marker 8OHdG, mineral/vitamin deficiencies are other functional metrics.
Photo credit: Smith et al, 2010
Fig. 1 The cecal appendix (a through l) or appendix-like structures (m through o) in a
Volative organic acids include polyamines, short chain fatty acids (VFA) and others. These can be quantified on the GDX/Metametrix GI function stool test and blood/urine organic acids testing. This test is the best on earth. It assesses both large and small intestine function, and additionally accurately pinpoints pathogenic overgrowth, parasites, and worms which are frequent invaders despite 'clean' air, water and soil in modern continents. If pathogens exist in the small intestines, caecum and/or large intestines, putrification of undigested fats, proteins and carbs occurs. Certain volative by-products are highly odiferous-- cadaverine, putrescene, spermidine, etc.
Treatment includes pathogen killing (charcoal, clay , herbals), healing the broken gut/brush border/GI peritalsis/acidity/pH, and replacing lost gut flora (commensal Firmicutes, Bacteroides, facultative anaerobes, SBO, good yeasts, etc).
The entire human gut has only ~17% of surfaces for fermentation compared with 50% for an animal like guinea pig. (TO ME, this is like the diff betw a select post-harvest wine versus mass produced Coors light.)
Bergman talks in-depth about VFAs . "Current estimates are that VFA contribute approximately 70% to the caloric requirements of ruminants, such as sheep and cattle, approximately 10% for humans, and approximately 20-30% for several other omnivorous or herbivorous animals. The amount of fiber in the diet undoubtedly affects the amount of VFA produced, and thus the contribution of VFA to the energy needs of the body could become considerably greater as the dietary fiber increases." I don't think we are gorillas ( 57.3% energy obtained from VFAs ) though some humans may exist as such (functional.. debatable?).
Role of Appendix and Failed Fecal Transplants
Our comparatively tiny human appendix is nearly non-functional yet appears to serve a purpose for maintaining maternal, birth- and early life-derived microbiota and biofilms. This is why -- I've heard -- that fecal transplants often fail 1-3 years post-transplant (anecdotal communication, Metametrix/GDX Tony Hoffman). Were these cases Paleo? Consuming fermented foods frequently? Root causes for dysbiosis/permeability identified and reversed? Toxins, mercury, pathogens addressed?
Appendectomies, Gluten Sensitivity, Gallbladders, Nutrigenomics and TMI
Not all animals have an appendix...... including members of my family; two out of 4 siblings have had surgical removal of the appendix. We also have 3/4 (diagnosed) autoimmune disorders. And 2/4 have documented gliadin sensitivity (me, positive fecal anti-gliadin sIgA in 2011 on Metametrix GI fx stool testing). Is there a connection? You tell me.
I'm Paleo because I'm protecting my gallbladder, appendix and other precious ~~. Not into chopped off organs, boobies , etc.
Integrative medicine, treatment and prevention for gallbladder disease HERE (Gaby 2009).
Recently my kids and I did 23andme genotype testing. Have you done it? It revealed many gluten-sensitivity related conditions we are susceptible to based on known SNP analysis (alkylosing spondylitis, primary biliary cirrhosis, T1DM, etc). Not a shock. I'm grateful for discovering the Paleo and gluten free diet in 2007, then functional medicine and intestinal permeability/gut dysbiosis in 2010. We have made appropriate changes and seen improvements -- some mild, some dramatic.
This is the year of personal nutrigenomics. We are negative for MTHFR but have the GSTT1 (glutathione, detox, heavy metals), deletion and are heterozygous for COMT (methylation -- detox of toxins, metabolism of adrenaline, dopamine, estrogens, 4OHE1, cortisol, etc).
Gallbladder stones and removal are super super super common in primary biliary cirrhosis (one of many celiac/silent-celiac conditions -- just like fatty liver, fatty pancreas, fatty heart, blah blah blah). Why? Look how anatomically close they are together to the liver, portal vein, stomach and duodenum/small intestine. When intestinal permeability allows undigested gluten through (or gluten just opens zonulin), gluten causes immunogenic havoc, scarring and immune system activation. Same with the appendix. When gluten and resident microbes translocate from the caecum/small/large intestines to proximal and distal organs, they hit neighbors the hardest. Appendectomies are mega-crazy-common (my dad's a surgeon; gluten paid for my college).
Often I hear stories that the spasms and pain remain despite surgery. Despite diligently avoiding 'high fat diets', they suffer (eating wholehealthylectins). It's not just the 'fat, forty, fertile female' (4F's) who are afflicted (as all hazed med students are taught). Males are affected too. Children are now affected .
It's a silent epidemic across the world in sync with vegetarianism (vegetarian males: 3-fold; vegetarian +alcohol, 7-fold) and westernized, Big Agra crop-users (like Saudi Arabia ).
Gluten? Dietary removal of gluten helps a ton as Gaby above reports (two studies in celiacs 1985 and 1999 ). Gluten is heat/cooking resistant. The toxic gliadin peptides can resist GI enzymatic digestion when microvilli DPP-IV is disabled (by mercury) and when brush border enzymes are missing (SIBO, gut dysbiosis, pathogens/parasites). At least 60 gliadin protein sequence s are immunotoxic, triggering immune system reactions for susceptible individuals. These were in relatively low concentration in ancient wheat but 50-100 years ago, transgenic hydridization and GMO techniques have bred (pun, bread) the concentration of the toxic gliadins to an estimated 500-fold amplication .
Peter at Hyperlipid cogently discusses Gluten and Gallbladders (circa 2008); good stuff, good comments.
Safe Guarding Appendices?
Smith et al talks about how the caecum is a "‘safe-house’ for biofilms containing commensal bacteria." How does antibiotics affect this? Antibiotics in food, cattle/chicken feed, eggs and their products? How do we revive extinct commensals and healthy biofilms.... Wish I knew definitively because there are few ways to test the contents of the caecum and appendix.
If I could repeat preconception, conception, birth, postnatal, and lactation periods with my kids, I would certainly do a million things differently from the gut and gut microbe perspectives.
Further Smith et al concludes on the relationship between the caecum (which contains a region of lymphoid tissue), gut microbiota and the immune system....
'Although microbial biofilms in the proximal large
Our Gut Anatomy and Physiology: Part Carnivore + Part Frugivore
The curious thing is that advanced hominids are not exclusive frugivores. Though it makes sense that we lost the capacity to synthesize Vitamin C and must find and outsource this to dietary Vitamin C, our digestive tract length, volume and capacity to produce low pH and secretions are akin to carnivores. Additionally, our shrunken small intestines possess really exceptional digestive capacities and efficient absorptive surfaces synonymous with carnivores, not herbivores (3-5X our height, not 10X as in herbivores).
Photo credit: Biocyclopedia .
Nearly ALL digestive work and absorption are concentrated in the small intestines, which varies in length by individuality, 15 -30 feet. This is why illness in the small intestines (SIBO/gut dysbiosis) disrupts all health, including even distant, peripheral tissues (brain, breasts, fat/belly, bones, joints, vasculature, gonads-b**ners), not only proximal (liver, pancreas, gallbladder). Energy dense food provide long acting fuel (fats, complex carbs). Our small intestines, gallbladder bile acids for fats and carbs, pancreatic enzymes (lipases, proteases, carb-ases) compensated. Our carnivorous small intestines are the super gift we acquired through evolution.
Our immune system is 70-80% based in the gut. Despite, our immunity being outsourced to microbes (caecal, appendix, intestines), only a fraction of our nutrition is (~10% from VFAs) because we obtain the energy from broken down, digested high-energy bonded food (e.g. fatty acids, complex carbs) in the small intestines. Our sophisticated and elite human small intestines suck all this energy up taking what first-pass at the liver misses. Human nutrition is super nutrient dense and fat based (my diet is 30-40% fat) allowing us to forgo chewing and grazing but only every 3-5 hours.
The remaining marginal allotment of our nutrition is brewed by symbiotic bacteria and yeasts... It's arguable that butyrate is both a nutrient for the intestinal cells as well as an extension of the ancient immune system for the entire body. Our hindgut (large intestines) continues methodical fermentation and microbial metabolite harvesting (organic acids, volatile fatty acids, B12, butyrate, other bacterial Firmicutes/Bacteroides end-products). It's absolutely not necessary to produce heaps and heaps of dung like our four-legged herbivore friends all day post-digestion without anal control.