Effect of graded hyperbaric atmospheric pressure on the quantity and composition of faecal flora

Figures & data

Table I.  Quantification of gastrointestinal flora after hyperbaric treatment for various time periods.

Type of bacteria	Normal count (cfu g^−1)	Pressures applied (kPa)	Colony-forming units (cfu g^−1) at different durations
			1 h	3 h	5 h
Total aerobes	1.9±0.17×10^6	122	1.8±0.19×10^6	2.3±0.213×10^6	3.2±0.29×10^7
		170	9.0±1.12×10^6	1.9±0.21×10^7	1.4±0.13×10^8
Total anaerobes	3.7±0.42×10^11	122	3.5±0.33×10^9	3.5±0.35×10^7	1.7±0.18×10^6
		170	1.5±0.12×10^9	4.8±0.51×10^6	1.0±0.21×10^4
E. coli	9.5±1.23×10^5	122	8.5±0.82×10^4	0.6±0.11×10^6	0.5±0.09×10^7
		170	1.5±0.14×10^5	0.5±0.08×10^7	1.5±0.15×10^8
Bifidobacterium spp.	4.0±0.07×10^4	122	1.3±0.14×10^4	2.7±0.32×10^2	1.1±0.21×10^2
		170	3.1±0.31×10^4	1.7±0.17×10^2	4.1±0.43×10^2
Clostridium perfringens	3.7±0.21×10^5	122	1.7±0.17×10^4	0.9±0.13 ×10^3	0.2±0.09×10^2
		170	1.5±0.12×10^4	0.14±0.05×10^2	Not detectable

Data are presented as mean ±SE.

Figure 1.  Comparative study of population size of total aerobes with time at 122 and 170 kPa. , regression coefficient (122 kPa-time); , regression coefficient (170 kPa-time); *step-wise; –, reduction in population size; +, increase in population size; #, time-specific, ⊺, standard error of mean.

Figure 2.  Comparative study of population size of E. coli with time at 122 and 170 kPa. , regression coefficient (122 kPa-time); , regression coefficient (170 kPa-time); *step-wise; –, reduction in population size; +, increase in population size; #, time-specific; ⊺, standard error of mean.

Figure 3.  Comparative study of population size of total anaerobes with time at 122 and 170 kPa. , regression coefficient (122 kPa-time); , regression coefficient (170 kPa-time); *step-wise; –, reduction in population size; +, increase in population size; #, time-specific; ⊺, standard error of mean.

Figure 4.  Comparative study of population size of Bifidobacterium spp. with time at 122 and 170 kPa. , regression coefficient (122 kPa-time); , regression coefficient (170 kPa-time); *step-wise; –, reduction in population size; +, increase in population size; #, time-specific; ⊺, standard error of mean.

Figure 5.  Comparative study of population size of Clostridium perfringens with time at 122 and 170 kPa. , regression coefficient (122 kPa-time); , regression coefficient (170 kPa-time); *step-wise; –, reduction in population size; +, increase in population size; #, time-specific; ⊺, standard error of mean.