The Potential for Probiotic Efficacy in Relation to the Consumption of Mixed Fermentation Ales.

Preamble: I wrote this essay for a college class and thought it should be posted out in the open for comments, criticism, and thoughtful discussion. As someone who brews and drinks a lot of Sour Ales it is a topic that I find intriguing.


We are going to take a look at and break down what makes something a probiotic and why they seem to be growing rapidly in popularity. Especially amongst the health conscience crowd. The science behind why they are so beneficial is only recently being discovered even though humans have been enjoying fermented foods for as long as they have been on the planet. Ales brewed with probiotic species of bacteria have been around as long as beer has been brewed but no one touts any potential gut health benefits. I believe that has a lot to do with the vast majority of modern beer being fermented through the use of pure isolated yeast strains. However, with the impressive growth of the craft beer industry and growing interest in old world beer styles, mixed fermentation ales are seeing a renaissance like come back. Can these beers be a good source of purported probiotic health benefits?

The Potential for Probiotic Efficacy in Relation to the Consumption of Mixed Fermentation Ales.

There was once a time when refrigeration was not so readily available in the home and the understanding of life on the micro scale was utterly non-existent. In fact, The German Beer Purity Law of 1516, also known as the Reinheitsgebot, had no mention of yeast until after its discovery in the late 1850’s by Louis Pasteur (Barnett, 2000). Our ancestors used a variety of methods to preserve food but one of the most prolific methods used was fermentation. This technique allowed for extended storage of essential food stuffs for months and sometimes years. Fermentation is the act in which a particular set of bacterial or fungal cultures convert nutrients into energy. The by-products of some fermenting cultures include acids that create an incredibly long lasting and shelf stable product. Cultivation of these specific cultures is done through the manipulation of the environment in which these nutrients are contained. Submersion of the substrate in a highly saline and anaerobic environment is the most common method for achieving this task. Today, those beneficial bacteria and fungi are commonly called Probiotics.

What is Probiotic?

In his book The Art of Fermentation, Sandor Ellix Katz broadly defines probiotics as “microbes that confer some benefit to the organism that ingests them” (2012). The term is rather new and any mention of it before the 1950’s are rare. The word is an amalgamation of the Latin preposition “pro”, which means “for” and the Greek word “biotic” meaning “life”. As mentioned before, refrigerators are a relatively new thing having only been around for a few generations. The ability to utilize refrigeration for preservation of food was limited to artic areas where the weather was optimum to do so. It wasn’t until the Industrial Revolution that huge blocks of ice could be shipped via railroad allowing for refrigeration in warmer climates. Fast forward a few decades to the advent of electricity and the vapor-compression cycle refrigerator and with it a decline in consumption of fermented foods. It’s a small historical bubble considering just how long humankind has been roaming the planet. That long period of time pre-refrigeration where our ancestors were eating loads of fermented foods led to these microorganisms taking up residence in our intestines, and thus today we have co-evolved to live in symbiosis with them.

Relationship to Mood and Health

This symbiotic relationship may go deeper than anyone could have imagined. The idea of consuming probiotics for health reasons is gaining traction and has led to some interesting scientific findings. A study done in 2015 suggests a strong relationship between a healthy gut microbiome and an individual’s happiness. The brain and the intestines are connected bi-directionally through neural, endocrine, and immune pathways. The microbiome of the gut affects this communication activating immune responses and causing the brain to release different chemicals that affect mood, such as Dopamine and Serotonin (Steenbergen, 2015).


For example, the microbiota produce neuroactive substances and their precursors    which can reach the brain via endocrine and afferent autonomic pathways. Also, bacterial products, such as the gram-negative endotoxins, can influence mood and cognitive functions via indirect and direct mechanisms (Steenbergen, 2015).

So, now that you know they are good for you.

How do we go about filling our bodies with billions upon billions of these beneficial microorganisms? Fortunately, as interest has increased so has the availability of probiotic products on the market’s shelves. There exists a plethora of pills, drinks, and other supplements labeled with promises of probiotic efficacy and correspondingly exorbitant prices. The cool part about probiotics is that you can produce them yourself at home for a fraction of the cost. It takes as little as some salt, water, and fresh vegetables packed tight in a jar to ferment and you can grow tons of Lactic Acid Bacteria on your kitchen countertop. However, I am going to focus on one particular product that I have been brewing for years and feel deserves a thorough inspection.

Mixed Fermented Ales.

Unless you are a complete beer geek like me then chances are that you have never heard of mixed fermentation ales before. Remember when I said that the German Beer Purity Law made no mention of yeast until Louis Pasteur’s discovery? Before pure isolated strains of yeast became available to brewers a wooden stick was used to stir and inoculate the beer with yeast. A good inoculation stick that brewed quality beer would be handed down through the generations as the microbes made home deep in the pores of the wood. Invariably, these sticks not only had yeast on them but also any number of bacteria as well. This led to a certain degree of souring of the beer depending on how long it aged. Not everyone wanted sour beer but some embraced it and have carried on the tradition of ales brewed using wild yeasts and bacteria. Some style examples that use Lactic Acid Bacteria for production are Berliner Wiesse, Gose, Gratzer, Flanders Red, Oud Bruin, and my personal favorite Lambic. Different techniques are used to introduce bacteria for different styles but the most intriguing to me is Lambic. Once the wort is brewed it is pumped into a large shallow copper pan, called a coolship, and allowed to cool overnight completely exposed to the elements. This is where any yeast or bacteria floating about in the surrounding air find their way into the wort and begin their fermentation. After cooling overnight and receiving the local microflora the Lambic is pumped into barrels where it will spend between one and four years fermenting and maturing before being bottled or blended with other barrels of different ages to produce a product called Geuze.


Because of the open air inoculation, Lambic is fermented by a number of probiotic species of microorganisms. These include various members of the Lactobacillus and Pediococcus families (Liles, 2014). The problem lies in the alcoholic content of Lambic as alcohol has shown to have a detrimental effect on gut health when taken to an extreme level. Alcoholics can suffer from severe liver disease and one study even shows that excessive alcohol consumption correlated to a decreased connectivity in the microbial network (Mutlu, 2012). Interestingly, another study showed that these ethanol-induced changes of the microbiome and liver were prevented in mice by supplementing with Lactobacillus rhamnosus; a species also found in Lambics (Bull-Otterson, 2013). Note that the alcohol by volume content of most Lambics are in the range of three to six percent.

Take Away

One of the more popular probiotic drinks I see popping up in almost every store is Kombucha; a type of fermented tea beverage. One of the biggest producers of Kombucha was hit with a class action lawsuit claiming that the label did not include the alcohol content, which was tested at over three percent (Esterl, 2015). Kombucha has long been held as a paragon in terms of probiotic sources. Why not mixed fermentation ales? According to at least one study, a single sip of beer can send Dopamine levels way up even without intoxication (Oberlin, 2013). It would seem that mixed fermentation ales have the potential to provide the consumer with active probiotics for a healthy gut and trigger a chemical reward mechanism releasing Dopamine and Serotonin; staving off depression and replacing it with happiness.


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     1850–1880. Yeast, 16, 755–771. Doi: #10.1002/1097-0061(20000615)16:8<755::AID-


Bull-Otterson L, Feng W, Kirpich I, Wang Y, Qin X, Liu Y, et al. (2013) Metagenomic Analyses

     of Alcohol Induced Pathogenic Alterations in the Intestinal Microbiome and the Effect of

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Liles, M. R. (2014), The Microbial Diversity of Traditional Spontaneously Fermented Lambic

     Beer, PLoS One, 9 (4) Doi: # 10.1371/journal.pone.0095384

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     Physiology, 302 (9), G966-G978. Doi: # 10.1152/ajpgi.00380.2011

Oberlin, B. G. (2013), Beer Flavor Provokes Striatal Dopamine Release in Male Drinkers:

     Mediation by Family History of Alcoholism, Neuropsychopharmacology, 38, 1617–1624.


Steenbergen, L. (2015), A randomized controlled trial to test the effect of multispecies probiotics

     on cognitive reactivity to sad mood, Brain, Behavior, and Immunity, 48, 258-264.

     Doi: #10.1016/j.bbi.2015.04.003



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