It is usual for many of us to experience fatigue and lethargy from time to time. The causes can range from trivial factors like poor diet and sleep to more serious factors like depression, fibromyalgia, or hypothyroidism. The gut microbiome has a lot to do with these fluctuating energy levels. They communicate with our brain (microbiome-gut-brain axis), and hence, can influence our mood and dynamism. How does supplementing probiotics hoist the sinking energy levels? Let’s delve a little deeper to understand this.
1. Boost the Immune System
For reasons acknowledged, we know that the friendly gut bacteria strengthen the defense mechanisms of our body and fend off harmful invaders. A healthy immune system is the initial step towards boosting our energy levels and getting us back on the track.
Probiotics activate a variety of immune cells including but not limited to macrophages, natural killer cell, and white blood cells. These cells shield against contracting diseases by warding off foreign agents. In order to communicate, these immune cells require the help of protein molecules, called cytokines. Probiotics also stimulate the release of these cytokines, thereby enabling the immune cells to interact and function. 
2. Burn Excessive Fat
Obesity, weight gain, and sedentary lifestyles are one of the primary causes of declining energy levels. The beneficial gut microbes help reduce the extra pound of flesh over your belly. Obesity has been associated with an imbalance in the microbial gut flora. In addition, it is observed that individuals with a flabby body have inflammation going on at the microscopic level. Probiotics ameliorate inflammation, restore the disturbed harmony of the gut flora, and accelerate weight loss. A body that is in a better shape is more energetic than that of a bad one. 
3. Help you Snooze Better and Alleviate Depression
Sometimes, depression is the root cause of insomnia and both sleep deprivation and depression individually contribute to fatigue. Owing to the bidirectional communication between the gut microbiota and the brain, probiotics appear to benefit sleep, mood, and energy levels – thus, also known as psychobiotics. Quality sleep not only reinvigorates your body but also aids in getting rid of various other factors that tend to make you lazy, such as weight gain.  The probiotic-induced increase in tryptophan might also account for these beneficial effects.  Tryptophan is an amino acid that converts into serotonin – the happy neurotransmitter. The vast majority of serotonin (around 90%) is synthesized in the gut and its production is regulated by the gut flora. 
4. Relieve GI issues and the associated Fatigue
In a randomized trial, patients with chronic fatigue syndrome (CFS) reported a significant reduction in the fatigue and anxiety symptoms after taking the probiotic.  People with CFS tend to experience digestive issues, primarily leaky gut and IBS. Using probiotics repairs the gut lining, modulate the gut microbiota, and mitigate gut inflammation in CFS, all of which reduce exhaustion and infuse vitality from inside out. 
Dr. Rasheem Huma
- Ashraf R, Shah NP. Immune system stimulation by probiotic microorganisms. Crit Rev Food Sci Nutr. 2014;54(7):938-56. doi: 10.1080/10408398.2011.619671.
- Kobyliak N, Conte C, Cammarota G, et al. Probiotics in prevention and treatment of obesity: a critical view. Nutrition & Metabolism. 2016;13:14. doi:10.1186/s12986-016-0067-0.
- Zhou L, Foster JA. Psychobiotics and the gut–brain axis: in the pursuit of happiness. Neuropsychiatric Disease and Treatment. 2015;11:715-723. doi:10.2147/NDT.S61997.
- Rao AV, Bested AC, Beaulne TM, et al. A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome. Gut Pathogens. 2009;1:6. doi:10.1186/1757-4749-1-6.
- Yano JM, Yu K, Donaldson GPet al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell. 2015;161(2):264-76. doi: 10.1016/j.cell.2015.02.047.
- Lakhan SE, Kirchgessner A. Gut inflammation in chronic fatigue syndrome. Nutrition & Metabolism. 2010;7:79. doi:10.1186/1743-7075-7-79.