Q: I have read your article entitled STERILE BOWEL THEORY. Well done on your article. It is going to be a great help to a great many people, me included.
You wrote :
- Bacterial fermentation is an inefficient source of energy. Birds with caeca utilize bacteria to help digest fibrous matter. Finches have no caeca.
- Finches have no resident bowel or so-called "friendly bacteria".
Since passerines do not have resident bacteria, then does this mean that the intestinal lining of passerines has not structurally evolved to being colonized by any bacteria, pathogenic or otherwise? The structure of the epithelial intestinal lining of passerines may well hold an answer as to HOW these birds maintain a sterile gut in the wild. The reason I ask this question is because much is made of the importance of giving Lactobacillus strains from a bird and not a cow, to chickens for example because the epithelial lining of chickens is better designed to accommodate avian as opposed to mammalian strains of the Lactobacillus. Please tell me if you think this is correct information.
If the intestinal lining of passerines has NOT structurally evolved to being colonized by bacteria, yeasts or protozoa, why is it that Candida, Avian Gastric Yeast, Campylobacter, E. coli and Trichomonas for example can invade the gastro intestinal tract of a finch and make them quite ill ? If the intestinal lining of passerines HAS structurally evolved to being colonized by any bacteria, yeasts or protozoa, then how is it possible for the gastro intestinal tract of passerines to remain sterile?
Weak organic acids such as apple cider vinegar and grapefruit seed extract solutions and certain herbs can suppress the growth of or probably even kill the bacteria and yeast from the beak and throat to the crop. But according to my information, the antibacterial, antifungal or antiprotozoal power of these weak inorganic acids and herbs will be substantially reduced from the stomach to the anus because they will be in turn chemically digested in the stomach of the passerine and so lose their antibacterial, etc. properties for the most part.
So it would seem that UNLESS the passerine is QUICK in ingesting the antibacterial, antifungal or antiprotozoal self medicating substance in time for the pathogens to be destroyed in THE CROP where food is stored initially before making its way to the stomach, any pathogens that the passerine ingests and are able to survive its digestive chemicals, WILL BE ABLE TO FLOURISH from the stomach to the anus. Please tell me if you think this is correct information.
You also wrote :
- The high metabolic rate of Oscine Passerines (eg finches) requires much more additional energy. In passerines more advanced and improved chemical digestion and intestinal absorption provide this additional energy.
Can you list the chemicals that are involved in passerine digestion please?
Do the gastric cells in the stomach lining produce these chemicals or are they produced in the body interior and then passed on to the stomach?
Regarding the improved intestinal absorption, where does absorption take place in a passerine and does this mean that bacterial, fungal and protozoa pathogens are able to be absorbed INTO THE BLOOD STREAM with improved efficiency or does this improved absorption only relate to digested food?
I am VERY interested in you as a person and in your work and I think the Sterile Bowel Theory rounds up some of the most important aspects of understanding our pet finches. :)
Sincerely, William Astor
A: Oscine passerines are highly evolved. They are a most recent family of passerine birds that has developed a highly sophisticated digestive system. Advanced methods of immunity (cell based) are used to control exposure to bowel infection.
It is not the structure of the epithelial lining that is the answer to how they maintain a sterile gut, but their entire immune system and organs that operate on a cellular level. There is a good reference book on immunity and the nature of disease. I believe you will find this text very enlightening. (1)
Finches are more susceptible to those organisms for which it has had little genetic and environmental exposure. This occurs, for example, in both Gouldians and Budgerigars. Both are a desert/arid-evolved species. Candida, E. coli, Coccidiosis and Trichomonosis are often rapidly fatal diseases in both species because these are diseases of a wet environment to which they have had little genetic exposure.
Campylobacter, for example, is of no concern for Bengalese finches, because they have an innate immunity to this disease. Gouldians, genetically, have had no exposure to Campylobacter and in juveniles this may also be a rapidly fatal disease. Megabacteria is a complex disease intimately related to the pH levels of the proventriculus. Conditions that change the acidity of the proventriculus (eg. Coccidiosis and Thrush infections) predispose birds to Megabacteria infections. Thrush (Candida albicans) colonizes keratinized surfaces only. Therefore Thrush cannot and does not colonize the small intestine. It will colonize the mouth, crop and gizzard. These are the organs where Megamix & KD exert their beneficial effect on Thrush and other germs in finches
We must remember all bowel infections originate from ingestion of contaminated sources. Organic acids are not corrosive but are used to change pH levels in the crop and sometimes in the bowel. The pH level changes we are talking about have a range of only 1 pH unit. Further information regarding the normal acidity of the finch digestive tract and the function of organic acids is explained in the Gouldian & Finch Health book. Organic acids may be buffered or un-buffered. Buffered organic acids will have an effect on the crop and beyond. Organic acids are not intended to cure disease but are used to help prevent alkaline related bowel diseases. They do not kill organisms but retard their multiplication. In doing so, they allow normal immune function (a complex chain of events) to re-establish a healthy bowel. The most important part of recovery is to identify the reasons the bowel has become alkaline.
In birds, the digestive process involves in part, proteolytic enzymes that are produced in the pancreas and stomach (proventriculus). Current knowledge concerning the digestion of food in birds is the result of scientific studies performed on poultry. Poultry belong to the Galliformes, a most primitive form of birds. In these birds, the crop, proventriculus, gizzard, small intestine and caeca are all involved in the digestive process. The gastric apparatus includes the proventriculus (secretes acid gastric juice and pepsin) and gizzard action (grinding action and acid proteolysis). The principle organ for chemical digestion and absorption is the small intestine. Here the chyme from the gizzard is neutralized by the highly buffered bile, pancreas juice and Sulcus Entricus. The pH, especially in the ileum, usually falls between 6-8. The chemical digestion of starch is effected largely in the small
intestine through activities of pancreatic amylase and of intestinal and pancreatic maltase. Lactose and sucrose are hydrolyzed by lactase and maltase respectively in the Sulcus Entricus.
Remember, absorption and nutrition takes place mostly in the stomach and small intestine. In some species, there is also cloacal reabsorption. Absorption of nutrients differs from absorption of microbes. The referenced texts listed at the end of the Sterile Gut Theory article are good references for the differences between absorption of nutrients and the absorption of microbes.
Thank you very much for your interesting questions.
1. MECHANISMS OF DISEASE. By Slauthon and Cooper, Published by Mosby
Q & A
Q: Dear Dr. Marshall,
"Buffered organic acids will have an effect on the crop and beyond."
If by this you mean all the way to the cloaca, then it means that alkaline related diseases in our pet finches could be a thing of the past. The all-important question therefore is: How can I make a buffered version of apple cider vinegar? Is it possible to make a buffered version of grapefruit seed extract [ not grapeseed extract ] solution? Is it possible to make a buffered version of various herbal teas?
A: The above three questions require the help of a chemist.
Q: You wrote...
"Organic acids are not intended to cure disease but are used to help prevent alkaline related bowel diseases. They do not kill organisms but retard their multiplication. In doing so, they allow normal immune function (a complex chain of events) to re-establish a healthy bowel."
Am I right in thinking that in slowing down pathogen multiplicaton, organic acids make it less likely for these pathogens to migrate to other parts of the body? In other words, am I right in thinking that it takes a certain population density of pathogens in the gut of the finch before any of those pathogens can migrate to other parts of the body ?
A: This is true. Overwhelming numbers of pathogens colonize the bowel lining and may then be absorbed into the bloodstream and then move to other parts of the body. Most have a local effect alone.
Q: You wrote...
"The most important part of recovery is to identify the reason.."
After several years of keeping Gouldians, I found that the birds would succumb to Candida sooner or later even though I gave them sterilized food and drink containers each day to eat and drink from and even though the air was not moist. In my bird-room at the moment, I also see evidence of a serious yeast problem. I have come up with the following explanation.
The cause I think is that in indoor bird-rooms of the Temperate Zone, bird breeders are forced to keep the windows shut for most of the year due to the intense cold air outside. This sets the stage for any air transmissible pathogens to wreak havoc on the birds. Many times I have heard of how bird-rooms were filled with dead birds when a bird with a virus e.g. Newcastle disease virus was introduced in one of the cages.
But even if the virus itself is not normally air transmissible, there is evidence to indicate that inhaling skin or dust particles may infect birds as well. Again air is playing a role. Fungi like Aspergillosis and Ergot in such a situation, can easily invade the birds because the spores cannot be spread and thinned out by the wind. In the still air of the indoor bird-room with shut windows, the birds have no choice but to breathe in the spores in the air until they succumb.
A: This is very true with airborne infection.
Q: Yeasts like Candida [I donít know whether Megabacteria can produce spores like Candida can] reproduce asexually by a process called budding but a few yeasts, such as Candida, also produce clusters of asexual reproductive spores. I think the reason why birds succumb so often to Candida in these situations is because this yeast can reproduce by air transmissible spores. The birds defecate. Their droppings contain Candida. In the watery environment of the dropping, the Candida reproduces and forms spores. At least this is what I think is happening. Unfortunately I do not have access to a laboratory of my own as you do.
A: I do not believe Candida is an airborne disease but certainly in a watery environment, it reproduces and forms spores. A dehumidifier or humidity control unit may be of great advantage.
Q: If what I am saying is correct, I am thinking that it may be a good idea to install a UVC box. According to what I have been told, it is UVC which kills all air pathogens but the scary bit about UVC is that it is extremely dangerous, leading to problems such as cancers and permanent eye damage - even total blindness in humans if it is not fully contained in a protective box. So I will have to proceed very carefully in building a UVC air purification device. What I have to do is find some material that will thoroughly absorb UVC radiation and somehow build a box that will contain a tube in there.
A: I believe airborne pathogens may be a problem and a UVC air purification system would be helpful.
Q: I have found an American website that sells these devices at : www.aircleanerforbirds.com
But they are prohibitively expensive. Cost is about 1100 Australian dollars and the HEPA filters each cost 110 dollars and they are to be replaced every 3 months.
I think using a UVC tube to get rid of air pathogens is a lot cheaper than having to replace a HEPA filter once every 3 months. This is the reason why I would be persuaded to build a UVC device myself.
Another aspect to this is that I think it would be stupid to have the air completely devoid of pathogens because it is important for the birds to be exposed to some pathogens so that their immune system will have be able to manufacture antibodies that the hens can pass on to their offspring so that the offspring in turn will be able to fight off pathogens, The idea is to REDUCE the number of air pathogens but NOT TO STERILIZE the air space in the bird-room.
A: I agree, although I have no experience with the UVC. Regular cleaning surface disinfection would be a good practice. This would decrease pathogen levels. Regular filter disinfection on air conditioner filters is also an excellent idea.
Q: I am wondering how many hours you would recommend leaving this UVC device switched on in a bird-room 5 meters x 3 m x 2 m in order to achieve this objective.
PS: This is Laraine speaking now... my new aviary has been set up to control the excessively high humidity that we experience here in Georgia. Therefore the birds are now in a humidity controlled, but not temperature controlled environment. My husband, being a HVAC technician, has designed a recycled air system which is UVC and HEPA filtered. My water supply for the birds has been UVC filtered for 2 years now. I will soon have an article on this web site relating the procedures involved and the effect this environment is having on my birds.
Sterile Bowel Theory
Adaptive Radiation the gene pool of a species undergoing changes, where the best suited gene becomes more frequent in the species' population, depending upon the environment. Over time the same species can diversify into other species; each trying to be as adaptive as possible in their environment.
Aerobic microbiological cultures culturing of droppings in the presence of oxygen (normal culture technique) as opposed to anaerobic (special technique) where no oxygen is present during culturing
Anaerobic Bacteria bacteria not capable of survival in the presence of oxygen (gangrene or botulism)
Autolysis the normal decaying process of tissue after death
Bacterial Fermentation a chemical change producing energy by the multiplication and growth of bacteria
Basal Metabolic Rate a body's metabolic rate while in a resting state
Caeca organ in the digestive tract of most birds, attached to the intestine in the area of the rectum, equivalent to the human appendix. Cellulose breakdown by bacteria occurs in the caeca of more primitive orders of birds. When present in a finch it is small and plays no part in digestion
Chyme lymphatic fluids, a semi-fluid mass of partly digested food after passing from the stomach into the intestines
Friendly Bacteria referring to bacteria which is naturally occurring in the gut for a particular species; as in yogurt cultures for human health
Galliformes a primitive order of birds including game birds (pheasants, grouse etc.) and domestic poultry
Granivore species seed eating birds
Hemorrhagic diathesis clotting defect associated with shock like syndrome which causes hemorrhage from the bowel and subsequent bleeding to death
Hydrolyzed breaking down food into a more usable form
Monophyletic derived from a single common ancestral form
Oscine the most recently developed group of Passerines which have a highly specialized vocal apparatus, songbirds
Paleogene, Medial and Teriary Periods geological time periods lasting millions of years
Pancreatic Amylase and Maltase enzymes used in digestion
Passerines birds belonging to an order of birds called Passeriniformes
Passeriniformes an order of birds which perch, comprising more than half of all living birds, songbirds
Proteolytic processes in digestion, the breaking down of proteins in food eaten to form simpler soluble products
Suboscines a more primitive group of Passeriniformes than Oscines
Sulcus Entricus folds in the intestinal lining
Symbiotic Bacteria "friendly bacteria" living within a species causing no harm to the host but playing a part in certain processes within the host organism
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