Probiotics and microbiota

With yesterday as World digestive health day , this is a great time to talk about gut health and the impact it can have within many areas of our biology.

 My research has taught me more about the importance of probiotics than I already knew.

Microbiota is the name given to the microbe population living in our intestine. Making up 90% of our cells! Containing 100s of trillions of microorganisms including at least 5000 different species of bacteria. The microbiota are important in nutrition, immunity and the brain.
The Microbiome is the combined genetic microorganisms in a particular environment.
Millions of years of co-evolution have moulded this human microorganism interaction into a symbiotic relationship where the gut bacteria contribute essentially to human nutrient metabolism and in return occupy a nutrient rich environment.



Children born vaginally get much needed microbes as they pass through the vaginal canal from the mother.  Yet those who are born by cesarian section tend to suffer more with asthma, allergies and leukaemia, (Neu, 2011.) Breast fed children have an intake of  sugars containing sialic acid which promotes infant growth through healthy microbiome, (Nestle Nutrition Insitiute), due to feeding the microbes.

Seratoin production is thought to be produced to the massive quantities of 90% within the gut, (Yano et al., 2015) which gives evidence to show those with altered microbiome will suffer further with depression and mental health issues, (Evrensel and Ceylan, 2015). A major role is played by the gut microbiome in bidirectional communication between the gut and brain. The Brain - gut axis communicates its systems between the Central Nervous System and Gastero Intestinal Tract, (Burokas, 2015.) As Burokas published in Science Direct, the gut microbiota can be a key regulator of mood, cognition, pain and obesity.
The immune cells are stimulated by a population of microbiota.  Those with impaired microbiome shows dendritic cells are reduced in the ability to stimulate pro inflammatory T cell responses.

Short chain fatty acids (SCFA) are produced in the gut and this aids the body immune systems and metabolic functions. When dietary fibre is fermented in the colon, short chain fatty acids are produced. They have many physiological roles in body functions.  Butyrate is important for colon health and is a  SCFA which arises from the bacterial fermentation of dietary fibre.  Produced by the probiotics, Butyrate is an important food for the cells lining the colon (colonocytes). Increasing the energy production and cell proliferation, there may be a protective element against colon cancer. The colonic inflammatory response if mediated by the presence of Butyrate. 70% of the energy needed for colonocytes is provided by this SCFA.  It is beleived there is a preventative and therapeutic potential to counteract inflammation mediated ulcerative colitis and colorectal cancer by the increase of modulation of the immune response and inhibiting tumour genesis.

Non starch polysaccharides  feed the microbiome.  Contributing to the host digestion (us).

http://bonvictor.blogspot.co.uk/2014/04/therapeutic-food-polysaccharides.html

Polyphenols are phytochemical fund in vegetables, legumes, chocolate, cranberries and green tea.  The consumption of these carries a reduced risk of chronic disease.  The low absorption rate in the upper gasteroinstestinal tract will benefit the colon.  Once the microflora break them down, they may change into bacteria themselves and possibly play a prebiotic role to modify the microbiota favourably.

Wu et al, (2011) studied the long term diet and the association with the microbiome.  Gut health is important.  As 70% of the immune system is in the gut, we need to know the factors affecting the microbiome. 

The largest affect is the host species, body mass, age, lifestyle and smoking.

Medium affecters: Antibiotic use

Medium-small: Drugs, exercise, genetics, pet co-habitation.

Small affect: Short term dietary intervention.


Can a daily supplement help?  I would say the best bet is to take one, while the stomach acid is quiet (IE not before or after food but about 2 hours either side) and definitely without adding any hot drinks. Heat will kill the important bacteria within the supplement.  Try it, you might be surprised how amazing you feel. 

Vitamin D and the fortification of milk

1941 saw the exposure of solar exposure and cancer risk.  Later studies found associations with low vitamin D levels associated with type 1 diabetes mellitus, autoimmune issues such as inflammatory bowel disease, MS and animal studies supported low vitamin D causing increased inflammation and cancer.

Adequate levels of 25 hydroxyvitamin d (OHD25) is considered a level of about 50nmol/L at the end of winter and 10-20nmol/L higher at the end of summer. The institute of medicine vs the endocrine society state the guidelines inappropriately conclude the benefits of vitamin d are at 75nmol/L 25OHD and above. Mistakenly concluding all persons with serum 25OHDlevels below 50nmol/L are deficient.

UK DoH recommends a plasma concentration of 25nmol/L

In 2016 public health england published a report advising that 10 micrograms are advised daily to support bones, teeth and muscle. This advice was published in line with recommendations from SACN to suggest this safe level for everyone over 4 years old. SACN did not take into account the vitamin D from sun exposure as the synthesis of the vitamin through the skin is complex. PHE advises that throughout the months from March until October the majority of the public gain enough vitamin D through sunlight and a balanced diet.  During the winter, dietary sources are relied on.  IT is difficult for people to meet the 10 microgram recommendation. Fortification of foods will assist with those who are less likely to get out in sunlight and those who do not consume enough naturally through diet.

Deficiency  - corresponds with blood levels with clinical evidence of bone disease such as rickets or osteomalacia. Once levels are below 20-25nmol/L a very high risk is present.
Insufficiency is a biochemical term. No clinical evidence of disease is present. PTH levels may be elevated in the blood.
Some studies do not differentiate yet the differentiation will really determine a change of numbers reported on the studies.

A large number of studies exist to show low 25OHD is associated with increased risk of cardiovascular disease, hypertension, type 2 diabetes mellitus, cancer, autoimmune disease and increased mortality.

Is vitamin D simply a good marker for health? Were the randomised control trials started early enough? Were these studies including looking at calcium?

Vitamin D toxicity is rare but potentially serious.
HypervitaminosisD is not caused by diet or sum exposure but rather intake of a supplement at levels of 60,000 IU a day for several months.  As the body regulates the vitamin D produced from sun absorption really very well, fortification may be an excellent answer to gain better status levels from the diet.  Fortified foods do not contain major amounts of vitamin D and are regulated closely.
Toxicity from vitamin D has a main consequence of hypercalcemia in the blood. Symptoms noted are nausea, increased urination and weakness.  Possible progression pathways are into bone pain, kidney problems and the formation of calcium stones. Treatment includes stopping vitamin D intake and restricting calcium in the diet.

Naturally occurring vitamin D can be found in fatty fish and fish liver oils.  A plant source of vitamin d is mushrooms although this is vitamin d2 yet animal products contain vitamin d3.

The largest source of dietary vitamin d is fortified foods.  Namely milk, orange juice and cereals.
Vitamin D is essential to bone metabolism and calcium absorption.
Vitamin D deficiency is common among older adults as they have impaired ability to synthesise vitamin d from the sun