METHOD FOR MAINTAINING INTESTIAL BACTERIA IN BALANCE
Background to Invention
The human digestive tract and intestines, similarly to those of all warm-blooded animals, consist of a number of different environments in terms of microbial action. Not all microbes can survive in all sections of the digestive tract. In addition, these parts of the system are a setting for competition between microbes, but also interaction associated with possibilities of survival, finding nutrition and propagation. In order to be able to function in the digestive tract or the various intestinal segments of which it is composed, the microbes must have properties that enable them to act in this environment. These properties may include the utilization of certain nutrients, ability to adhere to mucous membranes, tolerance to or production of antibiotics, or adaptation to certain types of environmental conditions, such as a low pH or partial pressure of oxygen.
After passing through the stomach with its typically acidic conditions, once the microbes reach the duodenum they can avail of more favourable and less demanding conditions in the human body. The pH, for example, is approx. 6-7. However, the body's defence system is on guard to fight microbial overgrowth in the intestine, and even in the various segments of the small intestine. It is commonly thought that unlike to what is found in the large intestine, rich microbiota or biofilms capable of using components of human food do not occur on the surfaces of the small intestine. The large intestine, on the other hand, acts as a type of sewer in the body, through which significant amounts of wastes are eliminated. Microbial growth in the small intestine is regulated by such as the secretion and occurrence of bile acids. Consequently, microbes with a high tolerance to bile acid usually flourish in this area.
It is a commonly held view that microbial balance in the intestine plays an important role in our state of health. This usually refers to the microbiota of the large intestine. Attempts are being made to improve the composition of the so-called normal flora in the large intestine by microbes contained in food or food supplements, mainly bacteria which in studies have been found to, or which are expected to, have a favourable influence on microbial balance, composition of the normal flora and our health and general condition. Studies strive to prove various favourable effects demonstrated as lower incidence rates of many infectious diseases and other illnesses. For example, it has been assumed that the
relatively low incidence rate of large intestine cancers in Finland compared to other Western countries would be a consequence of the high consumption of cultured milk products, such as yoghurts, in this country. More recent studies have also shown that microbial polysaccharides bind nutrients, preventing weight gain in test animals and thus the development of obesity problems (Park, 2001). It is also conceivable that many illnesses resulting from obesity, such as heart disease, diabetes, hypertension etc., or the underlying causes of such diseases, could be prevented by regulating the microbes or their action in the digestive tract.
The prevention of mild or even more severe diarrhoeas, including traveller's diarrhoea, is a significant area in which ingested microbial or bacterial preparates are used. The general idea is that once a favourable microbial balance in the intestine can be maintained, the microbes with positive effects will overrun those that could have harmful effects on the host, for example by causing illnesses. Directly proving such beneficial effects at the level of an individual is usually not possible, but they emerge in studies or long-term monitoring of large groups. It has thus been possible to draw up lists of those microbes and bacteria that are generally considered beneficial for the functioning of the intestine (here referring to the large intestine) and, similarly, those that are unfavourable. Further, it is not usually possible to determine the mechanisms of these effects at the level of interaction between the microbe and the host organism, however, and at best we can statistically establish that a certain microbe has a significant effect on the functioning of the host organism. An exception to this are vitamins produced by certain bacteria, including vitamin K, which has a direct impact on our state of health. These effects, however, are individual mechanisms, even if they had more wide-reaching consequences. Up till now, no principles have been presented that would unambiguously specify the overall composition or trend of the microbial flora and its precise method of action on human health.
When bacteria are included in the concept of microbes, the changes caused by microbial action in the microbiota of the digestive tract can be measured based on the occurrence of bacterial metabolites or waste products. These substances can be measured in the body in such as the blood stream, expired air, intestinal gases, on the skin or elsewhere with a sensor placed in this area or by analysing a sample collected in this area. Changes in action or composition of microbiota can also be gauged by analysing the contents of antibodies occurring in the blood stream, mucous membranes, faecal samples, saliva or elsewhere in the body.
Description of the Invention
In order to deliver probiotic or other microbes or bacteria with favourable effects to the target area, techniques need to be developed for their transfer. These techniques can be referred to as vectors. A vector can be a powder, solution, tablet, capsule or corresponding. In addition to being a vehicle for transporting the microbial strain, such techniques can further contain growth factors or nutrients needed by the microbes, or even antibiotics to prevent the action or to reduce the vitality of competing microbes. The usual aim is to work on microbial action in the large intestine. However, microbial action has also been found to occur in the small intestine and even in the stomach; in the typically acidic conditions (pH 1-2) of the stomach, such as helicobacteria have been found to create ecological niches that are favourable for them, the pH value of which is different from that of their surroundings.
The microbial strain to be transferred needs not only a vector but often also a means of getting the strain to colonise the right area and to maintain its functional ability there for as long as possible. For this puφose, methods can be developed to improve the adherence of desirable microbes to the various segments of the digestive tract. However, it has also been found that the composition of the human intestinal flora is mainly determined during a person's very first years of life. This is why we can assume that effectively achieving consequences that make an essential difference in an individual's state of health will, besides sufficiently long-term and continuous use, require:
1. microbial strain(s) with effective action (typically bacteria),
2. a working vector, and 3. ability of the strain to survive in the target area for as long as possible.
In any case, the effects will be limited and require continuous ingestion of the microbe. How, then, can we work on the microbes in our bodies, and on those in the digestive tract in particular, to ensure that they as a whole (cf. the concept of normal flora) can bring about health benefits for the host by their action?
Throughout the intestinal canal including the small intestine, facultatively anaerobic bacteria occur,
which are able to act either aerobically when oxygen is present, or anaerobically without oxygen. In order to enable them to implement the different metabolic modes, these bacteria have particular biochemical properties through which they can perform reactions necessary for their vital functions and growth. Contrary to what was commonly believed earlier, anaerobic metabolism can be as efficient as its aerobic counterpart, at least momentarily (Hakalehto et al. 2007). The end products of anaerobic metabolism are known as fermentation products.
Typical metabolic routes used by facultative anaerobic microbes include mixed acid fermentation, lactic acid fermentation, propionic acid fermentation and butylene glycol fermentation. The last- mentioned fermentation reaction differs from the others in that its products are mainly neutral, such as alcohols. What plays a crucial role for the digestive tract and the whole body is the type of facultative anaerobic bacteria that are dominant, or active, in the intestinal canal at any one time. This is particularly significant in the small intestine, where a considerable part of the nutrients used by the body are absorbed. While acid fermentation prevails, the intestinal pH goes down, favouring microbes that are able to act in conditions of a low pH value, whereas butylene glycol fermentation favours for example those microbes that are more tolerant to alcohols than others, such as many yeasts. While the bacteria performing butylene glycol fermentation turn organic acids occurring in the intestine into ethanol and butylene glycol, the pH value of the intestinal content goes up. On the other hand, a prerequisite for initiating butylene glycol fermentation is the occurrence of acids, and in particular acetic acid. Thus interacting partial reactions of various fermentation phenomena take place in the small intestine, and by utilising and regulating these, we can exert a favourable effect on the system's state of health. Consequently, the equilibrium between these facultative bacteria is crucially important for the microbial balance of the entire intestine and the individual's wellbeing. As an example, in extensive studies higher contents of butyric acid have been found in the intestines of obese people than in those of slim people (Turnbaugh, 2006). This shows that butylene glycol fermentation maintains neutral conditions, which facilitate the formation of butyric acid by butyric acid bacteria, e.g. many clostrides, in the intestine, and proves further that the bacteria performing butylene glycol fermentation play a larger role in the intestines of obese persons than in the digestive tracts of those who are slim. Another background factor to weight gain may be the fact that certain alcohols, such as ethylic alcohol, which are high-energy nutrients, are rapidly absorbed by the body in the intestine. In proportion, butylene glycol fermentation produces more ethanol than mixed acid fermentation. Thus the
composition of microbial flora plays an indirect role in the development of such illnesses as diabetes, heart diseases or hypertension, or in the prevention of their causes, such as the progress of obesity.
Forming, finding and maintaining a balance between acid fermentation processes and neutral alcohol fermentation processes of facultative anaerobic bacteria is a vital principle for the wellbeing of the entire digestive tract. This can be efficiently influenced by adding bacteria performing either acid fermentation or butylene glycol fermentation, or both, to the food or food supplements in the right proportions and at the right time. This balance can also be indirectly influenced by changing the internal status of the intestinal canal through food or nutritional or pharmaceutical components added to it. An example of this are various antibiotics, which can be used to control the development of microbial flora. On the other hand, the intake of alcohol favours microbes highly tolerant to alcohol, and on the other hand, ingesting various acids, such as acetic acid, changes the intestinal balance towards a more acidic direction. This is how influencing the action and mutual balance of facultative bacteria can in practice be efficiently utilised, especially when combined with the nutritional data of an individual and/or analysis results of his/her system or intestinal flora. As health-promoting products can be used ingested bacterial preparates or substances that affect bacterial action in the small intestine, especially as regards facultative bacteria, and the balance between bacterial strains performing acid fermentation and butylene glycol fermentation. This microbial action also plays a key role in the internal pH regulation of the small intestine.
If we wish to measure the composition of microbiota of the intestinal canal in particular to find out what types of facultative anaerobic microbes are working at a particular time, this can be achieved e.g. by measuring the contents and/or proportions of metabolites, organic acids and alcohols produced by precisely those microbes in the body, for example in the blood stream, expired air, intestinal gases or various tissues, or on the skin. We can also indirectly measure the short or long term impacts of these microbes on system parameters, such as blood pressure, blood test results, changes in skin pH, moisture or temperature, weight, body fat percentage, absorption of nutrients or other similar quantities. The composition of saliva, perspiration or other secretions can be analysed for this purpose. Further, the contents of antibodies in various parts of the body can be determined, for example in the blood stream, mucous membranes, saliva, various tissues or in faecal samples. The acidity levels of various parts of the system can also be monitored by measurements. All measurement data described here can be used
as a basis for the use of microbial strains or supplements affecting their action as described in this invention. The aim is at natural regulation of pH values in the intestine, and in the small intestine in particular, that promotes good health, thus improving and maintaining personal health and wellbeing.
While excessive absorption of high-energy alcohol compounds, for example in the intestine, can be influenced through microbial flora, an attempt can also be made to prevent excessive acid formation by acting on the microbial composition. This is why it is not possible to unambiguously state that ingesting certain microbes or improving their living conditions would always, at all times and in all circumstances be favourable to all individuals. Consequently, taking a bacterial supplement of the right type at the right time is crucial.
Typical members of facultative microbial flora are Escherichia coli and most other members of the family Enterobacteriaceae performing mixed acid fermentation, lactobacilli and streptococci performing lactic acid fermentation, and bacterial genera performing butylene glycol fermentation, Enterobacter, Klebsiella and Serratia.
References
Hakalehto, Elias; Pesola, Jouni; Heitto, Lauri; Narvanen, Ale; Heitto, Anneli.(2007) Aerobic and anaerobic growth modes and expression of type 1 fimbriae in Salmonella. Pathophysiology 14 (1): 61- 69.
Park, H.O.; Bang, Y.B.; Joung, H.J.; Kim, B.C.; Kim, H.R. (2001) Lactobacillus KCTC 0774BP and Acetobacter KCTC 0773BP for treatment or prevention of obesity and diabetes mellitus. US Patent N:o 6,808,703.
Turnbaugh, Peter J.; Ley, Ruth E.; Mahowald, Michael A.; Magrini, Vincent; Mardis, Elaine R.; Gordon, Jeffrey I. (2006) An obesity-associated gut microbiome with increased capacity for energy harvest. Nature vol.444: 1029-31.