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30 Jan 2015
We all know that it’s beneficial to boost your vitamin C levels during winter and certainly when you get a cold but is there anything else you can do to help boost your immunity? The latest research suggests that probiotics may well make it less likely to get a cold, and reduce the severity of it if you do catch one.
Acute psychological stress is positively associated with a cold/flu. A randomised, double-blind, placebo-controlled study1, which took place at the University of Florida, examined the effect of three strains of probiotic bacteria on the proportion of healthy days over a 6-week period in 581 academically stressed undergraduate students (during their finals) The students received Lactobacillus acidophilus Rosell-52, Bifidobacterium infantis Rosell-33, Bifidobacterium bifidum Rosell-71 or a placebo.
The results were interesting. 37% of the placebo group spent at least one day suffering from cold or flu symptoms. But only 24% of those taking the probiotic B. bifidum Rosell-71 became sick. Students who took B. bifidum Rosell-71 also reported fewer cold/flu episodes than the placebo group. And if they did catch a bug, it lasted an average of 1.8 days versus 2.4 days.
The reason they ran this research on stressed students as author Bobbi Langkamp-Henken, head of the Henken Laboratory at the University of Florida said “We know that a certain percentage of college students are going to become ill during fall finals. They are likely get sick because they are stressed, stay up all night studying, eat junk food, and live and study in close proximity with other students who have a cold or the flu.”
This study suggests therefore that a daily intake of Bifidobacterium bifidum Rosell-71 provides benefit related to cold/flu outcomes during acute stress. In addition a recent systematic review and meta-analysis2 the effect of probiotics, specifically Lactobacillus and Bifidobacterium strains, on the duration of acute respiratory infections in otherwise healthy children and adults was evaluated. The meta-analysis revealed a significantly fewer numbers of days of illness per person, shorter illness episodes by nearly a day as well as fewer numbers of days absent from day care/school/work in those participants who received a probiotic intervention than in those who had taken a placebo. The review therefore concluded that this provides evidence that probiotics reduce the duration of illness in otherwise healthy children and adults.
The amazing fact behind these findings is that our gut flora plays a massive role in mediating our entire immune response. In fact 70% of our immune system (follow link to Probiotics Learning Lab) lies in our intestinal tract. Therefore the healthier and more diverse our gut flora, the better.
Intestinal flora may help our immune system in several different ways.
Firstly it provides a physical barrier to colonisation by foreign, deleterious microbes. They do this simply by taking up space and being more proficient at utilising nutrients than the ‘invading bacteria’. This is why early colonisation of the intestinal tract is so important to keep a child’s immune system healthy.
Secondly, and amazingly intestinal flora actually communicates with certain aspects of the immune system to help them focus on invading microbes. It has been found that the bacteria in the gut actually ‘talks’ to the lymph nodes telling them which bacteria need to be attacked and which don’t! Amazing stuff!
Intestinal flora can also affect the growth and formation of certain organs responsible for immune health. And lets not forget that our gut flora affects the digestion and absorption of food (follow link to Probiotics Learning Lab) which ultimately affects our nutritional status and for example the absorption of zinc and vitamin C and antioxidants which all also contribute towards a healthy immunity.
More research is required on exactly when and how much probiotic can make the optimum difference. However a key outcome of this study is that the strain Bifidobacterium bifidum Rosell-71 had the most beneficial effect when given to adults and assessed for its immune supporting properties. Whilst in this study the strain Lactobacillus acidophilus Rosell-52 had no significant effect, we know that this latter strain has been tested and shown to have numerous health properties, for example in 2011 was found to help reduce anxiety when taken with another strain3. We also know that all three strains of bacteria studied in this cold and flu trial, when combined with a prebiotic, were found to help support immunity in children and reduced infection by 25%! So here we see how this study adds to the understanding that when it comes to probiotics, it is important to get the best strain for any given condition.
Either way, this year colds and flu have been rife so we are excitedly waiting for more research on this matter to give even more clarity as to the possible benefits of probiotics to our immune system.
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