Summary :
This article: (1) Hypothesizes an origin of milk kefir grains situated millions of years ago and allowing colonies of bacteria and yeasts ("wild" kefir grains) to participate in the immune defenses of their mammalian hosts by being present at the very beginning of their digestive system. (2) Suggests clues possibly involving palatal tonsil crypts in the management of a pre-digestive symbiotic flora present as a well enough organized scoby easy to grow in a lab. (3) Therefore it should be possible to get some of these "wild" scobys from an unweaned young goat or lamb. (4) A discovery that would lead to a better understanding of interactions between the human immune system and microbial communities (bacteria, yeasts and viruses).

Origin of the photos: Breastfeeding ibex, Milk kefir grains

Vocabulary and Preliminary Reasoning:

• Milk kefir : the most intriguing of the two main categories of kefir (the other being the fruit kefir) because of its origins in synergy with a number of pastoral communities since several millennia . The pastoral communities best known for their kefir grains being those from Caucasus and Tibet who gave access to their respective milk kefir strains (note : other pastoral communities may have been through the same stages without as much of attention from the western world).
• "Domesticated" Milk kefir grains: a scoby (symbiotic colony of bacteria and yeasts) to ferment milk in a gastronomic setting to make different kinds of yogurt or cheese.
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• "Wild" kefir grains: a supposed equivalent close enough from "domesticated" kefir grains, so in a natural cycle without human intervention it would shape physically and functionally close enough to the "domesticated" kefir. From there if this "wild" kefir exists: we can be almost sure of three things :
1. It must be in contact with milk from time to time, which considerably simplifies the areas to look for.
2. It must be in a symbiotic relationship with the concerned species of mammal, therefore useful for the hosts, which would give a new angle on the general benefits of kefir.
3. The mammals concerned are necessarily those who were privileged at the beginning of the pastoral agriculture, which arranges many possible tests since they are still available in a sufficiently similar shape. Note that other mammals probably host some equivalent of wild kefir grains, but to deal with them in the first stage would considerably complicate the process, not to mention that to confirm the phenomenon microscopically requires milk sufficiently close to the usual "wild" grain diet.
• "Domesticated" Kefir grains : kefir that can be used in our kitchen
• "Wild" does not necessarily mean in relation to wild animals, because it is very likely that "wild" kefir grains are present in some domesticated animals, in the sense that the animal is domesticated but not its micro-organisms, unless it undergoes general conditions that force a consequent modification of its microbiota! In practice, because of antibiotics, different foods etc. the risk is high!
• Simplification of terminology in the following texts:
• We are specifically interested in milk kefir grains, which implies that "kefir" if nothing else is specified refers to kefir grains and not as it is most often the case their production which is the kefir "yogurt".
• "Wild" kefir grains is simplified into wild kefir grains, then optionally into wild kefir or wild grains.
• "Domesticated" kefir grains is simplified into domesticated kefir grains, then optionally into domesticated kefir or kefir grains

Main reasoning:

The synergy of milk kefir with domesticated goats, sheep and cattle brings kefir grains closer to other mammals and points to a physiological logic where an ancestor of milk kefir grains participate actively in the metabolism and health of mammals! Important questions: Where does this ancestor hide? Is it still recognizable, and if we manage to flush it out, can we recreate from this ancestor an approximate equivalent of domesticated kefir grains? If this second step is successful what will be the differences observed with the standard strains, and will these differences clarify the origins and mixtures that led to the current kefir strains?

(Ref 1) S.R.Singer in a very "direct" article, cleverly points to the possible role of (Ref.2) crypts of the human palatine tonsils in the maintenance of a microbial probiotic flora allowing to prime the rest of the digestive tract! The logic of this argument is solid because what better than the very beginning of the digestive tract to select the right microorganisms! What is better than an organ with a strong affinity with the immune system (the palatine tonsils can be seen as the lymphatic organs of the throat) to perform a selection of micro-organisms: the multiplication of pathogens is slowed down by the immune cells while the probiotic strains are left free in a nutritious and temperate environment and by their competition and struggle with other strains, they slow down the multiplication of pathogenic strains from which there should not be much left since they share forces with the immune cells of the host. The finding that the aggregates taken from the crypts of the palatine tonsils (Ref.3) resemble kefir grains calls for more investigation, hence this article.

On the basis of these findings , it is of course necessary to study the tonsil crypts of unweaned goats or lambs that are thought to have been present in areas where the first grains of kefir have been domesticated. Obviously the shepherds in question have probably never been interested in the tonsils of their animals in this kind of context, but the versatility of the activities necessary for the welfare of small pastoral communities and the proximity between these activities implies that wild kefir probably unwittingly passed from their natural support to artificial carriers, typically some leather bags mentioned for storing milk.

Hypothesis: At the time what could be better than a unweaned goat or lamb stomach for storing milk? Especially since nature finally designed it partly for this task! And this certainly did not escape the shepherds of the time! Subsequently, the likelihood that lumpy bacteria and yeasts from the tonsils of the goats or lambs manage to squat the stomach-bag long enough to show off their usefulness for milk conservation is quite high considering a few centuries! The concerned shepherds would be quick to realize that some old stomach-sacs were working better than the standard ones to look at the grains and lumps that were trapped inside, and it could be how kefir grains were discovered.

A modern search for possible grains of wild kefir, would of course benefit from a direct interest on the concerned tonsil crypts rather than to repeat the complete procedure using a goat stomach. It is difficult to imagine the goat stomach experience in laboratory, not to mention that it would probably take dozens of trials until enough wild kernels broke off at the right moment of the tonsils of one of the goat or lamb involved! Clearly if it is really the natural process that led to the discovery of kefir grains, it could have taken a century or two until the right circumstances were met: using stomachs to store milk that one of the stomachs-besides is sufficiently impregnated, that the users are interested in the residues probably clogging the flow of the bag, that they have the idea to transfer residues in other containers! And this may also explains the fact that pastoral communities that have discovered kefir grains are quite rather rare.

From these findings the exploratory path is found: the first animals to be domesticated for their milk were most likely sheep or caprines because of their size easier to handle and their profile more versatile than cattle, sheep providing wool and goats with a great adaptation in mountainous terrain! This last point would tip the first trials towards goats given that several strains of milk kefir have a traceable origin in mountain areas. On the other hand the sheep are not too fearful on steep slopes and their wool is an excellent resource for mountain communities. The two types of milk kefir, one softer than the other, also suggest milder milk than the other (sheep's milk is sweeter than goat's milk), which implies that goats or sheep probably provide the same chances of starting on a good track. Therefore it's probably the easiest access for a given lab that could decide where the trials start.

Proposed paradigm to find and analyze wild kefir ancestor of domesticated kefir:

1. The ambivalence of choice is probably between goats and sheep, their macroscopic internal morphologies being nearly equivalent, goats appear qualitatively preferable because of apparently more robust health and a milk richer in minerals, so rich that it is difficult to find organic pasteurized goat milk in stores since it's harder to conserve compared to other pasteurized milk! In other words it is better suited to microorganisms than other milks, which is a good sign when we want to look for aggregates of microorganisms on or rather in animals.
2. Choose an unweaned goat.
3. Question? How would young, unweaned animals manage to generate wild kefir grains? Likely answer: the micro-organism strains are passed from generation to generation, first of all through the natural birth canal (absolutely avoid animals born by caesarean section, because the latter certainly interrupts the optimal transmission cycle of micro-organisms) the microorganisms are then evolved at each stage of lactation and are probably optimally positioned in the tonsils of the young animal toward the end of the lactation. The main problem in considering domestic sheep or goats comes from the fact that it is probably enough for a massive administration of antibiotics on one female upstream the generation or an animal born by cesarean section to affect the optimal composition of the tonsil flora of the examined animal. In other words, the ideal would be to look for bacterial aggregates on tonsils of wild ibex! On the other hand, everything is not lost for domestic animal testing since the kefir grains are relatively resistant and it would be enough to obtain a non optimal but multiplicative strain for the operation to be successful.
4. In practice, it should be possible for a veterinarian to extract a few samples from the tonsillar crypts of a young, unweaned and healthy goat or lamb without harming it. It is important to note that we do not look for tonsillitis which in this kind of context could be considered as degenerate wild kefir grains, but softer and elastic agglomerates (it would be useful at this stage of the extraction to have practical habits to differentiate between young kefir grains (soft, spongiform) and old used grains (harder and smooth).
5. Caution: Samples taken from tonsils of dead animals are at high risk of failure by various contamination and chemical or mechanical interactions: waiting time, oxidation, unknown reactions between potential kefir grains and dead animal tissues, pre- and post-mortem cleaning procedures, etc. Far too many unknowns.
6. Laboratory-generated kefir grains (If they come to existence) should not be propagated in the community. On one hand it's likely that the ancestral grains have accumulated additional qualities with their "domestication", qualities that could be lost in case of crossovers! On the other hand, the tonsils are known to have the possibility to harbor all kinds of microbial flora, some of which are pathogenic, also including (quite rare but better careful than sorry) even more disturbing entities such as inverted prions.

Implications for success and possible follow-up of research:

1. Almost all mammals have more or less varied tonsils and equivalent structures are also found in birds (list probably not exhaustive), but this seems to point to the importance of regularly taking care of the bacterial flora from the very beginning of the digestive tract.
2. If the hypothesis of this article is confirmed, kefir grains as wild kefir are projected tens of millions of years in the past , not just in the form of microbial ancestors lost in the wild, but in the form of tonsils scobys actively participating in the immune system of their hosts.
3. The ability of milk kefir to maintain its probiotic characteristics despite sometimes dubious manipulations confirms the robustness of this mammalian-microbes symbiosis. Seen almost like an external and complementary immune system.
4. The three preceding points underline the interest of the milk kefir after a major stress of the intestinal flora, especially in people deprived of their tonsils.
5. After finding human equivalents of wild kefir grains, probably again at the level of the palatine tonsils, it would be extremely logical to advise probiotics to people deprived of tonsils, thus deprived of personal production.
6. Personal analyzes of the tonsillar flora would make it possible to know its effectiveness in case of doubts. Ablations of the tonsils could probably be replaced by less invasive treatments including optimum bacterial flora repopulation.
7. Newborns born by caesarean section and thus deprived of a huge part of the microbial flora that should have been provided by their mothers at the time of birth could be supplemented with optimized kefir cultures.
8. People who have undergone antibiotic treatments could remake their microbiota more effectively.
9. The differences between wild kefir and domestic kefir could:
   • Improve our understanding of the evolution of these organisms while probably allowing a kind of historical back pedaling with a better vision of the original starting points.
   • Eventually show a true adaptation to external storages (room temperature jars for the western world today), which would provide additional information on the bacterial and fungal capacities for this kind of survival.
10. The "domestic" kefir is probably improved considering the possible interactions with its human consumer! Over the millennia of microorganisms promoting the survival of kefir and its handling were probably inserted into the scoby! What are they? What are they exactly for? Do they have an animal and / or human origin?
11. Milk kefir grains are probably impregnated deep in their DNA by the imprint of their original host, which would also explain why kefir grains support a very large amount of iodine (tested with lugol), they accelerate their multiplication with doses of lugol dissolved in milk that would probably correspond to lethal doses for a human being if the same concentration was swallowed for a liter of kefir. It sort of hints to the proximity between amygdala and thyroid. If many genes had passed between host and wild kefir grains, should we look for them in kefir yeasts which as mammalian cells have a nuclei, these cooperation genes inserted into these nuclei would give extraordinary information about the origins and symbiotic abilities of kefir grains within their hosts

References :
(*) beware some photos are unappetizing

Seminal article and main clues :

• Réf. 1 : S.R.Singer : ... A New Theory on Why You Have Tonsils and What Happens If You Lose Them.
• Réf. 2 : (*) Cryptes des amygdales palatines.
• Réf. 3 : (*) Tonsillolithe.

Milk Kefir :

• Traditional kefir of Caucasus.

Tonsils of sheep:

• (*) Scielo.Conicyt.cl : Microarchitecture of the Palatine Tonsil in Sheep.
• Nih.gov : Formation of lymphoepithelial tissue in the sheep's palatine tonsil.
• (*) ResearchGate.net : Numerous white nodules on the dorsal side of the soft palate (tonsil of the soft palate).

Tonsils of goats:

• WATCH: DWR uses helicopter, diver to 'mug' mountain goats + checking teeth and tonsils.

Miscellaneous:

• Comparaison des amygdales d'ovins, de caprins, de porc et d'équidés.
• High prevalence of salmonella enterica subsp. diarizonae in tonsils of sheep at slaughter.